The Core Electron Microscopy Facility at Dana Farber Cancer Institute located in Boston, Massachusetts has a position immediately open for a full time EM Technician to assist in daily operation of the central research facility. Requirements include: B.S. or equivalent in life sciences; one to two years experience working as an EM technician or histology technician; familiar with scanning and transmission electron microscopy and associated preparative techniques, including tissue processing, Epoxy resin embedding, ultrathin sectioning and contrast staining, immunogold staining, and dark room procedure. Computer knowledge including word processing and data base programs is required. Cryoultramicrotomy skill is desirable but not required. Office management skills including filing, ordering and billing are also helpful. M-F, 40h/W, Salary $20-25K/year with excellent benefit. DFCI is an equal opportunity Employer. If interested, please send by email resume to Yuhui Xu, MD,PhD, at the following address: Yuhui_Xu-at-dfci.harvard.edu. Or contact by telephone at (617)632-5753. Fax (617)632-5165.
I'd like to know the ways that people use for analyzing SAD patterns from samples that are polycrystalline where the patterns are not complete rings and where there are two or more phases present. I'm interested in techniques that employ an automated method for determining the d-spacings present.
Currently, I am using a program that takes the digital SAD image and gives a circularly integrated 1-dimensional pattern that can be directly compared with X-ray diffraction patterns and either the JCPDS or NIST Crystal Databases. It works very well for complete rings, but some modifications were necessary for "spotty" patterns because the integration process doesn't take account of the geometric problems with more dark pixels in the outer radii. Right now the software has a couple of options on how to integrate "spotty" patterns, but they are kludgy.
Please drop me a line and let me know how you do them.
I have stumbled across a reference to Hoffman modulation contrast (HMC). Briefly, the article states that HMC allows 3-D like images. It is possible to view specimens through plastic dishes (a limitation of Nomarski DIC ?) and to view thick samples (a limitation of phase contrast).
Can anyone tell me more about this technique please?
Many thanks, Felicity
Felicity Lawrence
Analytical Electron Microscopy Facility Queensland University of Technology GPO Box 2434, Brisbane 4000 Australia
I have 200 MB colour images from microscopy on the hard disc in the image analyser Quantimet 570 color. Quantimet save colour images in the form image file: red, green and blue.
How print this images on the color ?
Krzysztof Jan Hubner
{hubner-at-IOd.krakow.pl}
Foundry Research Institute Research Materials Department, Head Structural and Physical Research Laboratory Zakopianska 73 Call +48 12 605022 ext. 356 30-148 KRAKOW - POLAND Fax +48 12 665478, + 48 12 660870 :-)
Ann Arbor Science Publishers, Inc. P.O. Box 1425 Ann Arbor, Michigan 48106
This reference is out of print (if memory serves me correctly) but many light microscopists have the reference. It was being sold at one time on CD-Rom.
It may be available still at the following:
Microscope Publications Ltd - Products Available from Microscope Publications Ltd. The Microscope Journal. Books in The Microscope Series. Other McRI Publications. Return to McRI Home.. --http://www.mcri.org/McRI_products.html
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Hello,
I have stumbled across a reference to Hoffman modulation contrast (HMC). Briefly, the article states that HMC allows 3-D like images. It is possible to view specimens through plastic dishes (a limitation of Nomarski DIC ?) and to view thick samples (a limitation of phase contrast).
Can anyone tell me more about this technique please?
Many thanks, Felicity
Felicity Lawrence
Analytical Electron Microscopy Facility Queensland University of Technology GPO Box 2434, Brisbane 4000 Australia
Since it is the lack of sufficient numbers of grains and different orientations that are resposible for spotty ring patterns, our solution has been to move the sample holder while the diffraction pattern is being exposed. We move both the X-Y drives and the tilt. This takes some practice in setting the right exposure time and speed of sample movement, but more complete rings can be obtained.
Ciao for now, Ken
} I'd like to know the ways that people use for analyzing SAD patterns from } samples that are polycrystalline where the patterns are not complete rings and } where there are two or more phases present. I'm interested in techniques } that employ an automated method for determining the d-spacings present. } } Currently, I am using a program that takes the digital SAD image and gives a } circularly integrated 1-dimensional pattern that can be directly compared with } X-ray diffraction patterns and either the JCPDS or NIST Crystal Databases. It } works very well for complete rings, but some modifications were necessary for } "spotty" patterns because the integration process doesn't take account of the } geometric problems with more dark pixels in the outer radii. Right now the } software has a couple of options on how to integrate "spotty" patterns, but } they are kludgy. } } Please drop me a line and let me know how you do them. } } - -Scott Walck
Kenneth JT Livi Department of Earth and Planetary Sciences 34th and Charles Streets The Johns Hopkins University Baltimore, Maryland 21218
I too collect SAD patterns digitally and analyze them live time by searching the PDF and EDD data. I use a couple of image processing programs to reduce the data, however, I never do anything automatically since there is often so much data in a SAD pattern, such as double diffraction or satellite spots. Therefore, I chose manually which rings or partial rings or spots I want to contribute to the pattern being searched. Be careful also when interpreting intensities in the TEM. It can be misleading. For what it is worth ...
Jim Heuer General Electric Co. (510) 862-4501 heuerj-at-vncpo1.ne.ge.com
1. Scott, save that question and ask it again in the "Meet the Experts" Diffraction session at this year's MSA meeting. We are trying something new to us at MSA (credit to the Society of Vacuum Coaters who've had this type of session for some time now). We have identified areas in the physical sciences and separately in the biological sciences where people occasionally need some answers. Electron diffraction is one of the areas to be addressed in this year's meeting, chaired by Alwyn Eades. Essentially we will have an empty room with a slide and transparency projector in place. Alwyn, and anyone else Alwyn chooses to join him, sits up front, people come in, take a seat and ask questions. Either Alwyn or someone else in the room is likely to know the answer. The room is scheduled for an hour. Your question is exactly what we expect to have asked.
The other two physical science sessions confirmed are 'vacuum' with Wil Bigelow and 'phys sci specimen preparation' with Reza Alani and me. We are also considering a session on 'phys sci technologist training' but haven't firmed this up yet. Joe Mascorro is responsible overall for the biological side of this and I'm doing the physical side. We plan to put more detailed info on MSA's WWW server soon.
2. I prefer to manually pick out diffraction spots and partial rings as belonging to a particular phase in a mixture. I might take a diff pattern of a specimen that is being translated during exposure to bring more grains into the aperture to get a better grasp on which phase is which and some idea of intensities (I know, intensities are unreliable but in the absence of very strong texture, strong is strong and weak is weak and this info often helps solve phases)--but I wouldn't try to take d-spacings from a translated pattern. For accurate d-spacings the entire process has to have a precision of 1% or better. This is do-able but not easy. Electronic (video/CCD cameras,...) data collection is marginal at the 1% precision level in my experience with photographic methods ranging in precision from "adequate" to "poor." Instrumental techniques, like making sure your specimen is at the eucentric height and proper lens focus and adjustment are big factors. Diffraction was actually more precise in old 5 lens (1960s) TEMs compared to now. Split objective lenses with condensor minilenses that interact with the field below the specimen might make for high resolution images and small analysis spots but they cost the user in terms of diffraction precision. IMHO :-)
I have been asked the following question: ----------------------------------- I am looking for a peice to our old steroplotter it is 1940's model is a officine galieo made by the galieo company of italy. model number is smg10. do not know if you know this info but maybe you can stir in right direction . ---------------------------------- Does anyone have any information about this "galieo company of italy"? Sounds like this is a real museum piece.
Chuck
====================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
Look for us! ############################ WWW: http://www.2spi.com ############################ =====================================================
I have been asked the following question: ----------------------------------- I am looking for a peice to our old steroplotter it is 1940's model is a officine galieo made by the galieo company of italy. model number is smg10. do not know if you know this info but maybe you can stir in right direction . ---------------------------------- Does anyone have any information about this "galieo company of italy"? Sounds like this is a real museum piece.
Chuck
====================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
Look for us! ############################ WWW: http://www.2spi.com ############################ =====================================================
} Hello, } } I have stumbled across a reference to Hoffman modulation contrast (HMC). } Briefly, the article states that HMC allows 3-D like images. It is possible } to view specimens through plastic dishes (a limitation of Nomarski DIC ?) } and to view thick samples (a limitation of phase contrast). } } Can anyone tell me more about this technique please? } } Many thanks, } Felicity } } Felicity Lawrence
First, let me recommend Slayter & Slayter, "Light and Electron Microscopy". (Note: Nomarski=Differential Interference Contrast) Briefly simplified, with the attendent inaccuracies that implies: Hoffman Modulation works in a similar way to Nomarski, the major difference being that Nomarski is based on phase constrast between a specimen and a reference ray and Hoffman works by "amplitude modulation" between specimen and reference rays. Nomarski generates its specimen and reference rays with polarizers, Hoffman does not use polarized light. This means that Nomarski has troubles with optically active materials--specimens, plastic petri plates, etc.--whereas Hoffman does not. I've found that Nomarski seems to work better with thinner specimens (tho' I have used Nomarski with zooplankton), Hoffman with thicker, but I've read comments to the opposite. Hoffman does not have the troubles with convex/concave specimens that Phase Contrast does. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Microscopy Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
I asked for information about Hoffman Modulation Contrast (HMC) and received the following replies :
1. I used Hoffmann several years ago to view dispersed polyethylene in PET sheeting for trays. I agree that HMC produces the illusion of 3-D, but to me the strong advantage was the ability to alter the "amount" of phase contrast which reduces the "halo" around particles. It seemed to work the best on multi-phase samples in which the difference between the refractive index of the phases were too high for phase contrast but too low for brightfield.
I use to cut my thin section samples by hand, so I do not have thickness data, but I found the thin samples gave better photomicrographs then thick samples. [F.K.]
2. If you have not already, you may wish to look at Hoffman's original article. [Hoffman (1977) J Microscopy 110, 205-22. [D.C.]
3. Try:
The Particle Atlas, ed. 2 Volume V pp. 1155-57
Ann Arbor Science Publishers, Inc. P.O. Box 1425 Ann Arbor, Michigan 48106
This reference is out of print (if memory serves me correctly) but many light microscopists have the reference. It was being sold at one time on CD-Rom.
It may be available still at the following:
Microscope Publications Ltd - Products Available from Microscope Publications Ltd. The Microscope Journal. Books in The Microscope Series. Other McRI Publications. Return to McRI Home.. --http://www.mcri.org/McRI_products.html [J.H.]
4. Have you tried Zeiss VAREL contrast? [D.F.]
5. We've used Hoffman illumination to good advantage with semi-thin (0.5 um ) sections of Spurr's resin embedded material (Sex. Plant. Reprod. 9:1-16). When we purchased the objective and condenser, the salesperson stressed that it was particularly useful for tissue culture observation with inverted optical scopes. It also gives nice images on wet mounts, at a considerably lower cost than Nomarski - although in my opinion, Nomarski is still superior for this purpose. The thickest material we looked at was probably ca. 10 um (squashes of Arabidopsis microsporocytes) and they looked good - but no plastic in that case. I did hear recently that Hoffman's patent is expiring and that the microscope companies that were originally not interested in his development are coming out with their "own" versions, so it's hard to tell what will happen to prices. I think we paid about $2000 U.S. for a 100X objective and condenser about 5 years ago. Maybe they're (Hoffman) having a sale now. [H.O.]
6. The system does indeed work and give DIC like images through plastic. It is not as good as DIC and from my experience, definitiey begins to degrade at higher magnification (the 40x lens is usable, but not great). I have only looked at cells, and not at thick tissue, so I don't know how suitable it is. Have a dealer bring in the system and try it out. It is not hard to add to an existing microscope. It is just a polarizer and a special lens with a polarizer element in it. I have them listed at 516-484-8882 Modulations Optics Inc. in New York. Hope this helps- Dave
Hoffmann modulation will allow you to view through plastic dishes. Neither Hoffmann modulation nor Differential Interference Contrast (Nomarski) give you 3D views...they are shadow casting methods depending on contrast generation due to differences in refractive index of different parts of the specimen. The reference for Hoffman Modulation is Hoffman, R. 1977. J. Microscp. 110:205. [N.A.]
7. First let me recommend Slayter & Slayter, "Light and Electron Microscopy". (Note: Nomarski = Differential Interference Contrast) Briefly simplified, with the attendent inaccuracies that implies : Hoffman Modulation works in a similar way to Nomarski, the major difference being that Nomarski is based on phase contrast between a specimen and a reference ray and Hoffman works by "amplitude modulation" between specimen and reference rays. Nomarski generates its specimen and reference rays with polarizers, Hoffman does not use polarized light. This means that Nomarski has troubles with optically active materials -- specimens, plastic petri plates, etc. -- whereas Hoffman does not. I've found that Nomarski seems to work better with thinner specimens (tho' I have used Nomarski with zooplankton), Hoffman with thicker, but I've read comments to the opposite. Hoffman does not have the troubles with convex/concave specimens that Phase Contrast does. [P.O.]
Felicity Lawrence
Analytical Electron Microscopy Facility Queensland University of Technology GPO Box 2434, Brisbane 4000 Australia
DOES ANYONE KNOW OF A USED ELECTRON MICROSCOPE VENDOR ON EAST COAST THAT BUYS OLD EM'S WE HAVE A JEOL 100B FOR SALE I HAVE SEEN CATALOGS FROM A BUSINESS CALLED "BID SERVICE" BUT I DIDNT SAVE ANY OF THEM
DOES ANYONE KNOW OF A USED ELECTRON MICROSCOPE VENDOR ON EAST COAST THAT BUYS OLD EM'S WE HAVE A JEOL 100B FOR SALE I HAVE SEEN CATALOGS FROM A BUSINESS CALLED "BID SERVICE" BUT I DIDNT SAVE ANY OF THEM
THANX IN ADVANCE
The "BID Service" phone number is (908) 775-8300.
Margaret E. Bisher
NEC Research Institute 4 Independence Way Princeton, NJ 08540. Tel.: (609) 951-2629 Fax: (609) 951-2496 e-mail: peggy-at-research.nj.nec.com
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} Hello, } } I have stumbled across a reference to Hoffman modulation contrast (HMC). } Briefly, the article states that HMC allows 3-D like images. It is possible } to view specimens through plastic dishes (a limitation of Nomarski DIC ?) } and to view thick samples (a limitation of phase contrast). } } Can anyone tell me more about this technique please? } } Many thanks, } Felicity } } Felicity Lawrence
First, let me recommend Slayter & Slayter, "Light and Electron Microscopy". (Note: Nomarski=Differential Interference Contrast) Briefly simplified, with the attendent inaccuracies that implies: Hoffman Modulation works in a similar way to Nomarski, the major difference being that Nomarski is based on phase constrast between a specimen and a reference ray and Hoffman works by "amplitude modulation" between specimen and reference rays. Nomarski generates its specimen and reference rays with polarizers, Hoffman does not use polarized light. This means that Nomarski has troubles with optically active materials--specimens, plastic petri plates, etc.--whereas Hoffman does not. I've found that Nomarski seems to work better with thinner specimens (tho' I have used Nomarski with zooplankton), Hoffman with thicker, but I've read comments to the opposite. Hoffman does not have the troubles with convex/concave specimens that Phase Contrast does. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Microscopy Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
A short course in SEM for biologists will be held at the University of Florida March 10-13 and again May 5-8. This is for the beginner. Interested persons should see our WWW site for details.
www.biotech.ufl.edu/~emcl ******************************************************* G.W. Erdos, Ph.D. Phone: 352-392-1295 Scientific Director, ICBR Electron Microscopy Core Lab 218 Carr Hall Fax: 352-846-0251 University of Florida E-mail: gwe-at-biotech.ufl.edu Gainesville, FL 32611 http://www.biotech.ufl.edu/~emcl/ Home of the #1 Gators ***** "Many shall run to and fro, and knowledge shall be increased" Daniel 12:4
In response to your inquiry about Hoffman Modulation Contrast and the kind response by jeharper-at-amoco.com mentioning The Particle Atlas, I can provide the following information. The Particle Atlas Electronic Edition (PAE2) is available from the following suppliers:
MicroDataware P. O. Box 12755 Berkeley CA 94712 sshaffer-at-microdataware.com
McCrone Research Institute 2820 S. Michigan Avenue Chicago, IL 60616 ndaerr-at-mcri.org 1-312-842-7105 voice 1-312-842-1078 fax
McCrone Accessories and Components 850 Pasquinelli Drive Westmont, IL 60559 1-708-887-7100 voice 1-708-887-7764 fax
McCrone Scientific Ltd. McCrone House 155A Leighton Road London NW5 2RD UNITED KINGDOM 011 441 71 267-7199 voice 011 441 71 267-3383 fax
If and when I can get problems with my internet service provider ironed out I will put the MicroDataware web pages, with further information about the Particle Atlas Electronic Edition, back up at http://www.microdataware.com. However, for now this site is not active.
Best of luck with your HMC work. It is an excellent technique for contrast enhancement, yielding images similar in many ways to DIC.
Although it is a bit lengthy for a posting to a list server, I have included full text of the sections of the PAE2 dealing with HMC below. Information on this excellent technique is sufficiently scarce that I thought many of the readers of the list might find it, and the literature references, useful.
Steve Shaffer
Text on Hoffman Modulation Contrast from the Particle Atlas follows:
***************************************** Chapter 2: Techniques for Particle Characterization {snip} R. Hoffman Modulation Contrast
1. Introduction
A common problem in microscopy is object contrast. If the substage aperture has to be closed in order to see the object, the resolving power is severely reduced. Particle microscopists often attempt to maintain high resolution and at the same time enhance contrast by mounting their samples in Aroclor. This excellent mountant has a conveniently high refractive index, usually sufficiently different from the particles to permit use of a full condenser aperture and, hence, obtain maximum resolution.
Often, however, particle microscopists resort to a contrast enhancement technique such as darkfield, Zernike phase contrast or Nomarski differential interference contrast, DIC . Such methods increase the sensitivity of refractive index measurement besides making all particles more distinctly visible. On occasion, the mounting medium is not a matter of choice, and particle contrast cannot then be enhanced by choosing mountants of very different refractive index. Particles on a membrane filter, for example, are difficult to see unless the filter structure is cleared by immersing the filter and particles in a liquid matching the filter in refractive index. This is seldom the best liquid in which to study the particles. Counting asbestos fibers, usually chrysotile with indices near 1.55, is not easily done when the clearing liquid has to have an index of 1.51. Usually, in this situation, microscopists have turned to phase contrast to make the fibers easier to size and count.
2. Optics
A new contrast enhancement method with advantages over other methods has been developed by Hoffman and Gross since the publication of The Particle Atlas in 1973. Now termed Hoffman modulation contrast (HMC), this new system can be adapted easily to most microscopes. It enhances contrast without the halos characteristic of phase contrast and without apparent loss of resolution. The image, like DIC, is "three-dimensional" and permits optical sectioning of an object with little or no interference from detail above or below best focus. Also, like DIC, the effect is directional, and both detect phase gradients by converting opposite gradients into lighter or darker images compared to the background. The means by which this is accomplished is very different, however, for the two procedures. Nomarski, in his DIC system, uses a modified Wollaston prism to produce two sheared rays of light, separated by only about 1 micrometer, passing through the object, introduces interference with resulting darker borders on the other side. This produces a shadow effect and the three-dimensional appearance.
Hoffman and Gross, on the other hand, accomplish similar results by quite different optical principles. Figure 281 shows schematically the component required to convert a brightfield microscope for modulation contrast. A system of apertures below the substage condenser is conjugate with a matching system of apertures in the objective back focal plant. A full-aperture polarizing filter below the substage apertures permits variable contrast enhancement. It is essential that the substage apertures be fitted into a rotatable gliding mount in order to be able to accurately register their image with respect to a second set of apertures in the objective back focal (Fourier) plane.
3. Apparatus
The light source and microscope should be arranged for Kohler illumination. The aperture system below the substage condenser has about one-half its aperture covered (lengthwise) with a polarizing filter P1 (P2 is also a polarizer). The modulator has three regions differing in transmittance: D, 1%; G, 15%; and B, 100%. The 15% transmittance G region is not a polarizing filter.
In practice, the gray region (G) is displaced to one edge of the Fourier plane, and the dark region (D) lies outside the exit pupil of the objective. The bright region (B) then fills about 90% of the Fourier plane. Resolution of the system, approximating lambda/2NAobj. in spite of the restricted substage aperture, is maximized by off-setting the gray (G) region to the edge of the exit pupil. When the gray region is centered on the microscope optical axis, the resolution then approximates lambda/NAobj.. Removal of the aperture plate permits use of the HMC objective for ordinary brightfield study.
The system is so simple that many microscopists might consider making their own apertures; however, this same simplicity also makes professional conversion relatively low in cost. Note, however, that 3X to 100X objectives can be fitted for HMC, but each objective to be so used must be modified; each objective also requires its own substage aperture system.
4. Applications
HMC will be most useful for the biologist who always has contrast problems with tissue sections (Figures 282 and 286). From a strictly contrast point-of-view it will still be best to use mounting media having refractive indices very different from the object; however, when this is impossible, HMC will be very useful. Even when the indices of object and mount are quite different, HMC helps in the delineation of fine detail. Forensic scientists will find it helpful for semen examination and especially for species identification of spermatozoa by study of their morphological features. Banding of the sperm head as well as length and diameter measurement of the neck portions are much easier with HMC. HMC will also be helpful in enhancing contrast during refractive index measurement by the immersion method. In short, HMC will be useful as a replacement for phase contrast because of the better image, and for DIC because it is considerably cheaper.
Anyone interested in the theory of HMC can refer to the Hoffman and Gross papers, especially the 1977 paper in the Journal of Microscopy.
Hoffman, R., "The modulation contrast microscopy," Am. Lab. (1978).
Hoffman, R., and L. Gross, "Modulation contrast microscopy," Turtox News, 2-5, (1975).
Hoffman, R., and L. Gross, "The modulation contrast microscope," Nature 254, 586 (1975).
Hoffman, R., and L. Gross, "The modulation contrast microscope," Microscope 23, No. 4, 264 (1975).
Hoffman, R., and L. Gross, "The modulation contrast microscope," Appl. Opt. 14, 1169 (1975).
Hoffman, R., and L. Gross, "The modulation contrast microscope," J. Microsc. 110, 205 (1977).
Hoffman, R., and L. Gross, "The modulation contrast microscope," Chapter in Microstructural Science, Vol. IV, E. W. Filer et al., Eds., American Elsevier, New York, 1977, p. 287.
***************************************** End of excerpts from the Particle Atlas Electronic Edition
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I asked for information about Hoffman Modulation Contrast (HMC) and received the following replies :
1. I used Hoffmann several years ago to view dispersed polyethylene in PET sheeting for trays. I agree that HMC produces the illusion of 3-D, but to me the strong advantage was the ability to alter the "amount" of phase contrast which reduces the "halo" around particles. It seemed to work the best on multi-phase samples in which the difference between the refractive index of the phases were too high for phase contrast but too low for brightfield.
I use to cut my thin section samples by hand, so I do not have thickness data, but I found the thin samples gave better photomicrographs then thick samples. [F.K.]
2. If you have not already, you may wish to look at Hoffman's original article. [Hoffman (1977) J Microscopy 110, 205-22. [D.C.]
3. Try:
The Particle Atlas, ed. 2 Volume V pp. 1155-57
Ann Arbor Science Publishers, Inc. P.O. Box 1425 Ann Arbor, Michigan 48106
This reference is out of print (if memory serves me correctly) but many light microscopists have the reference. It was being sold at one time on CD-Rom.
It may be available still at the following:
Microscope Publications Ltd - Products Available from Microscope Publications Ltd. The Microscope Journal. Books in The Microscope Series. Other McRI Publications. Return to McRI Home.. --http://www.mcri.org/McRI_products.html [J.H.]
4. Have you tried Zeiss VAREL contrast? [D.F.]
5. We've used Hoffman illumination to good advantage with semi-thin (0.5 um ) sections of Spurr's resin embedded material (Sex. Plant. Reprod. 9:1-16). When we purchased the objective and condenser, the salesperson stressed that it was particularly useful for tissue culture observation with inverted optical scopes. It also gives nice images on wet mounts, at a considerably lower cost than Nomarski - although in my opinion, Nomarski is still superior for this purpose. The thickest material we looked at was probably ca. 10 um (squashes of Arabidopsis microsporocytes) and they looked good - but no plastic in that case. I did hear recently that Hoffman's patent is expiring and that the microscope companies that were originally not interested in his development are coming out with their "own" versions, so it's hard to tell what will happen to prices. I think we paid about $2000 U.S. for a 100X objective and condenser about 5 years ago. Maybe they're (Hoffman) having a sale now. [H.O.]
6. The system does indeed work and give DIC like images through plastic. It is not as good as DIC and from my experience, definitiey begins to degrade at higher magnification (the 40x lens is usable, but not great). I have only looked at cells, and not at thick tissue, so I don't know how suitable it is. Have a dealer bring in the system and try it out. It is not hard to add to an existing microscope. It is just a polarizer and a special lens with a polarizer element in it. I have them listed at 516-484-8882 Modulations Optics Inc. in New York. Hope this helps- Dave
Hoffmann modulation will allow you to view through plastic dishes. Neither Hoffmann modulation nor Differential Interference Contrast (Nomarski) give you 3D views...they are shadow casting methods depending on contrast generation due to differences in refractive index of different parts of the specimen. The reference for Hoffman Modulation is Hoffman, R. 1977. J. Microscp. 110:205. [N.A.]
7. First let me recommend Slayter & Slayter, "Light and Electron Microscopy". (Note: Nomarski = Differential Interference Contrast) Briefly simplified, with the attendent inaccuracies that implies : Hoffman Modulation works in a similar way to Nomarski, the major difference being that Nomarski is based on phase contrast between a specimen and a reference ray and Hoffman works by "amplitude modulation" between specimen and reference rays. Nomarski generates its specimen and reference rays with polarizers, Hoffman does not use polarized light. This means that Nomarski has troubles with optically active materials -- specimens, plastic petri plates, etc. -- whereas Hoffman does not. I've found that Nomarski seems to work better with thinner specimens (tho' I have used Nomarski with zooplankton), Hoffman with thicker, but I've read comments to the opposite. Hoffman does not have the troubles with convex/concave specimens that Phase Contrast does. [P.O.]
Felicity Lawrence
Analytical Electron Microscopy Facility Queensland University of Technology GPO Box 2434, Brisbane 4000 Australia
Of course the Bid Service buys old EM's. I have seen over 6 old SEMs in their catalog. Otherwise I think you can try CBI(Capovani Brother's Inc.). Their email and address are:
cbi-at-capovani.com ph: 518.346.8347 fax: 518.381.9578 704 Corporations Park Scotia, Ny 12302
Good luck.
Tong
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I can recommend two very good sources for information on the Poisson Distribution. 1. Statistical Analysis in Chemistry & Chemical Engr. by Bennett & Franklin, John Wiley, 1954, p115 (This is an older book, but one that is written very clearly and in a very practical orientation. It covers the basic statistical concepts plus a thorough treatment of several common experimental design schemes for analyzing data from complex multi-variable experiments.)
2. Data Reduction and Error Analysis for the Physical Sciences, by P. R. Bevington, McGraw-Hill, 1969, p.36. This is another very practical book that deals particularly with the counting of photons and particles. It also contains algorithms for (in FORTRAN) for a wide variety of data analysis processes (deconvoluting spectral data, smoothing, peak area measurement, etc).
wow this is service thanx to all the replys for bidservice info happened to check the web and the right place to start is at Microworld resource net at http://www.mwrn.com/product/microscope/used.htm pointed to at least 6-7 companies
sorry joe at ddk about the SHOUT ing didnt know caps lock was so loud
I have just setup a microscope system for use with an existing picosecond pulsed laser to perform time-resolved fluorescence measurements. Currently we are using an inverted Zeiss Axiovert IM-35 and a photon-counting photomultiplier to perform spot-measurements. We are considering an upgrade to the present system to include a confocal scanning attachment in order to be able to acquire images as well as fluorescence decays. The laser we are considering is a Ti-sapphire with picosecond/femtosecond pulse capabilities, so that 2-photon excitation imaging would also be possible. Could anybody recommend an attachment capable of adding confocal capabilities to our Zeiss microscope? Any comments, suggestions, warnings, etc. would be greatly appreciated.
Thank you in advance.
Massimo Sassaroli, D.Sc. Dept. of Physiology & Biophysics Box 1218 Mount Sinai School of Medicine 1 Gustave L. Levy Pl. New York, NY 10029-6574
We have a Hitachi S-800 FESEM from the pre-digital days. We have been saving up our pennies to purchase either the Hitachi PCI system (many pennies) or the GW Electronics Printerface (fewer pennies). We got as far as getting a great new PC before we ran out of pennies. However, we did purchase with the FESEM a S-5010 TV Scanning Device, which basically converts Hitachi's propriatary signal to NTSC, primarily for output to a VCR. This device does not give the same image as on the CRT, and one has to use specific accelerating voltages and working distances and read the magnification off a chart. And the magnification range is very limited, making it useless for our high mag-high res work. However, I suspect it could be used as an interim device for grabbing images with the PC. I have snaked a long cable from it to the Mac and used the Power PC's video board to get (rather lousy) images. I would now like to get a video board for the new Pentium and do the same (or better). I don't know video boards. I am looking for advice! If I could get some digital images for the price of a video board, I would be thrilled! I promise disgusting weather reports to all who respond...
Thank you all for being such a friendly and helpful group!
Aloha, Tina
New Stuff! http://www.pbrc.hawaii.edu/bemf/microangelo Simple SEM animations at- http://pbrc.hawaii.edu/bemf/microangelo/gif_animations.html **************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
Hi all, I'll keep this short. I've been asked to post concerning the availability of two free TEM's here at the University of Iowa. There is a Siemans 101 and a Phillips 201. To the best of my knowledge, they are both in operating condition. For further information, contact Kenneth Moore at {kenneth-moore-at-uiowa.edu} or phone 319-335-8143. Thank you.
A month ago I asked for comments and experiences relating to allergic reactions to the use of acrylate embedding media. To date, I have received the following responses. I thank you all for your input.
Have attached the file of responses as direct e-mail seems to be difficult or impossible with my internet connector...
I just began getting replies to my request for advice on video boards for digital capture from my analog FESEM. Yes, I DO want a high-quality system - eventually. But until the University recovers from fiscal insults, I am talking about a SUPER-CHEAP way out. I can get a (not very nice) NTSC signal from a Hitachi device I already have, so I only want right now a card to stick in the PC (which is in the same room) for something like $200 to $400. Like what I can pay for out of my own pocket. I am still very interested in people's experiences with full systems, since that is where we eventually want to go, but I'm only trying to kludge something together for the moment! I will happily take all opinions on both "real" digital acquisition systems and "kludge" solutions!
Yeah, I know it's silly to count pennies when I have a $200K 'scope, but right now even Kimwipes(tm) are at a premium!
**************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
I just began getting replies to my request for advice on video boards for digital capture from my analog FESEM. Yes, I DO want a high-quality system - eventually. But until the University recovers from fiscal insults, I am talking about a SUPER-CHEAP way out. I can get a (not very nice) NTSC signal from a Hitachi device I already have, so I only want right now a card to stick in the PC (which is in the same room) for something like $200 to $400. Like what I can pay for out of my own pocket. I am still very interested in people's experiences with full systems, since that is where we eventually want to go, but I'm only trying to kludge something together for the moment! I will happily take all opinions on both "real" digital acquisition systems and "kludge" solutions!
Yeah, I know it's silly to count pennies when I have a $200K 'scope, but right now even Kimwipes(tm) are at a premium!
**************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
Division for Microscopy and Microanalysis Department of Physics Chalmers University of Technology S-412 96 G=F6teborg, Sweden
Two PhD student positions are open in Materials Science/Engineering with the following contents.
1. CONTACT AND ADHESION BETWEEN SMALL PARTICLES. Contact and spontaneous adhesion between small particles (10-100 nm) will be studied with analytical and high resolution electron microscopy. The spontaneous adhesion between small particles depends on surface forces. The accompanying stress fields, which are visible in the electron microscope, give a unique possibility in detail to study the elastic and plastic deformations which are associated with contact. This effect is very importannt within areas such a friction, wear, fretting, electrical contacts and handling of fine powders.
2. NANOSTRUCTURED MATERIALS. GRAIN BOUNDARIES AND MECHANICAL PROPERTIES. Nanostructured material exhibit many new and interesting properties due to their extremely fine-grained structure ( { 100 nm). The reduction in grain size leads to unique mechanical, physical and chemical properties compared with conventional materials with the same composition. The mechanism behind the formation and the stability of different nanostructures and the resulting properties are however poorly understood. The idea with the current program is to establish a systematic knowledge about the grain boundary zone in nanostructured materials and their influence on the mechanical properties. A combination of advanced electron microscope and analytical methods will be used.
The two projects lie in the boundary area between physics/materials science. In both projects a Philips CM 200 FEG with Gatan imaging filter, slow scan CCD-camera, energy dispersive X-ray analysis and PEELS will be used.
Qualifications: Master of Science or equivalent within physics/materials science. A knowledge of electron microscopy is estimated but is not absolutely necessary. A vivid interest for mathematics is appreciated.
Further information: Professor Anders Tholen,=20 Division for Microscopy and Microanalysis Department of Physics Chalmers University of Technology SS-412 96 Goteborg, Sweden
Tina, I am a microscopist in the research laboratories of Eastman Chemical Company. Although I haven't had any personal experience with a product called "Snappy", which is an adapter for NTSC image capture on a PC, it might be just what you are looking for. In sells for under $200. A friend of mine at Clinch Valley College is using one on an AMRAY SEM and is quite pleased.
I just checked out your BEMF pages and they are quite nice! One note, though. The net address you listed in your note (see copy below) to the IT list-server left out the "bemf" part.
} Mahalo, } Tina } } http://www.pbrc.hawaii.edu/microangelo } http://www.pbrc.hawaii.edu/microangelo/gif_animations.html }
The address I used was
http://www.pbrc.hawaii.edu/bemf/microangelo/
Dr. Dennis B. Barr | 333 DDDDD 333 DDDDD Eastman Chemical Company | 3 3 D D 3 3 D D Microscopy and Morphology | 3 D D 3 D D Research Laboratory | 33 D D 33 D D P.O. Box 1972 | 3 D D 3 D D Kingsport, TN 37662-5150 | 3 3 D D 3 3 D D | 333 DDDDD 333 DDDDD Voice: 423/229-2188 | E-mail: dennbarr-at-eastman.com | IMAGE IMAGE FAX: 423/229-4558 |----------------------------------------------------- (Cross your eyes to see the 3 dimensional image above)
About a month ago I asked for experiences with allergy experiences when using acrylate embedding media. I received the responses below. I will be sending several editions as there are many and I have had difficulties with my e-mail server...too big a gulp, I guess...
1) I used Lowicryl for a brief time, while waiting for funding for a cryokit. I developed a pretty good contact dermatitis/allergic reaction within a few uses, precluding me using it. Also I found the smell very allergenic (runny nose etc) Luckily I got the cryokit, and was able to return to a NON allergenic system (sugar!) very soon. Since then I have been convinced that the acrylics are bad news..... Good luck with your investigations.
Simon
2) Their was a program on NOVA that concerned itself with Sick Building Syndrome. It covered several people in a hospital environment that aquired hyper-allergies from the gloves and chemicals used. You might want to check the references that the film used... It was a good..... Check with WGBH in Boston (PBS Station) for more information on the film.....
I have seen several technicians and operators become sick from the fumes from roughing pumps and from Freon that is widely used.. Anyone of us could be next with the wide variety of chemical we use and the increasing amount of contact we have....
Walter Protheroe
3) Over the years, I have picked up some sense of the way these different acrylics seem to act on different persons.
The Lowicryl resins seem to be the worst, and LRWhite (and I thought up until now, also Unicryl) the least reactive. Technovit I have not had any knowledge about.
Chuck
Regards, Don Cox ******************************************************** Donald P. Cox, Ph.D., M.B.A. GOLDMARK BIOLOGICALS/D.P. COX ASSOCIATES 437 Lock Street, Phillipsburg, NJ 08865-2764 (908) 859-2631 - - (908) 859-2875-FAX E-Mail: goldmrkr-at-fast.net/goldmarker-at-aol.com Web Page: http://members.aol.com/goldmarker
~~~"Goldmarking is everlasting probing!"~~~ ********************************************************
About a month ago I asked for experiences with allergy experiences when using acrylate embedding media. This is the second series..
5) My predecessor here had a lot of problems using watyer soluble Durcupan resin. He manifested what we now realise was contact dermatitis, with skin blemishing, cracking and peeling. He was also sensitive to the cured blocks, at least certainly to their dust (we used to cure in ice cube trays and then cut specimens out with a hacksaw for mounting prior to ultramicrotomy as routine).
With best wishes - Keith Ryan
6) Don, I realize that you asked about acrylic plastics, but just as a note: my former supervisor in a clinical EM lab had a strong contact allergy to uncured epoxy plastics. We had to be careful not to leave residue where she could come in contact with it, she'd break out in blisters in about 15 min.
Doug
7) have you got this reference? It seems to be a key one referring to several others:
Tobler, M. and Freiburghaus (1990); Occupational risks of (meth)acrylate compounds in embedding media for electron microscopy Journal of Microscopy 160: 291-298
Good luck in your search.
Malcolm Haswell
8) Don, I don't know what to tell you except that this allergy is common, I am severly allergic to Lowicryl, and have been told that if I'm exposed to it again on my hands, I may lose the use of my hands. It took me 6 months to get the feeling back in my finger tips, and my fingers were so bad they were purple black. Also, the fumes from methacrylates etc is of no help to my chronic asthma.
I usually run into someone with the same problem in the Histology / EM field where ever I go.
We ordered the only gloves we found impermiable, H-4 Gloves from Monsanto, but they are very ackward to work in.
Lou Ann
----------------------
Regards, Don Cox ******************************************************** Donald P. Cox, Ph.D., M.B.A. GOLDMARK BIOLOGICALS/D.P. COX ASSOCIATES 437 Lock Street, Phillipsburg, NJ 08865-2764 (908) 859-2631 - - (908) 859-2875-FAX E-Mail: goldmrkr-at-fast.net/goldmarker-at-aol.com Web Page: http://members.aol.com/goldmarker
~~~"Goldmarking is everlasting probing!"~~~ ********************************************************
I would like to obtain an old Balzers EVM 052/052 Electron Beam Gun power supply. I'm also interested in any unused or unwanted Balzers Freeze Fracture systems or parts.
Dear Tina, I'm afraid that the best you will be able to do is a lousy image, no matter what video board you get. The rapid scan image on any SEM is very poor, that is why slow scan capture is used for digital imaging. You wrote: } } We have a Hitachi S-800 FESEM from the pre-digital days. We have been } saving up our pennies to purchase either the Hitachi PCI system (many } pennies) or the GW Electronics Printerface (fewer pennies). We got as far } as getting a great new PC before we ran out of pennies. However, we did } purchase with the FESEM a S-5010 TV Scanning Device, which basically } converts Hitachi's propriatary signal to NTSC, primarily for output to a } VCR. This device does not give the same image as on the CRT, and one has } to use specific accelerating voltages and working distances and read the } magnification off a chart. And the magnification range is very limited, } making it useless for our high mag-high res work. However, I suspect it } could be used as an interim device for grabbing images with the PC. I } have snaked a long cable from it to the Mac and used the Power PC's video } board to get (rather lousy) images. I would now like to get a video board } for the new Pentium and do the same (or better). I don't know video } boards. I am looking for advice! If I could get some digital images for } the price of a video board, I would be thrilled! I promise disgusting } weather reports to all who respond... } } Thank you all for being such a friendly and helpful group!
Regards, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
Colleagues - Continuing.... You'll never ask again, I'll bet...!
11) } i do not recall her name off hand, but if you contact rmc,inc } tucson,arizona,(they probably have a web page) and ask who was their } biological instructor at their ultra microtomy conference this year in } oct . I specifically remember, and i was surprised that she repeatedly } cautioned the group about similar severe allergy-proned } individual-reactions being rather common. I believe she also may be } linked to this newsgroup and may reply directly.
I'm that instructor. I don't have any specific medical information; just the sort of word-of-mouth stories that are appearing here (which I'm saving for next year's Materials Microtomy course!). I'd appreciate comments from knowledgable MDs. I know that I read a paper some years ago about similar reactions to the acrylic resins used to cement metal joints into bone in orthopaedic surgery...
Caroline Schooley
12) Hi: I myself have through the years developed a reaction to acrylates. My field is polymers and I am frequently in contact with acrylates. The monomer is the problem not the polymer. Wear gloves and always work in the hood. If you do get exposed wash or shower as soon as possible. The reaction is cumulative and becomes worse with each exposure. Good luck Olga L. Shaffer
13) Here at IBM, there is a fairly extensive Industrial Safety and Hygiene program. In our training classes, it was explained to us that epoxies, etc., are "sensitizers" as are Poison Ivy, Poison Oak, and Poison Sumac. Some people may have a reaction on their first exposure. Others may have a reaction after repeated exposures have "sensitized" them. The reactions will most likely increase in sevearity with each additional exposure. There are a few that never show a reaction. I know people that were never affected by Poison Ivy when they were children, but had severe reactions when exposed as an adult.
Precautions during use (what we are required to do): * The resins and hardeners are stored in a vented cabinet. * Weighing, mixing, and sitting to cure are done in a vented hood. *** Protective Appearal *** *** Nitrile Gloves - eg. Nitrilite by Ansell Edmont Note: Latex gloves were not accepted * Goggles * Plastic Chemical Apron
Hi again,
(Please ignore my spelling typo's, it was late last night.) I meant to mention that the Nitrilite gloves are lightweight surgical type gloves, and very easy to work in.
Hope this helps.
Darrell Miles ******************************************************** Donald P. Cox, Ph.D., M.B.A. GOLDMARK BIOLOGICALS/D.P. COX ASSOCIATES 437 Lock Street, Phillipsburg, NJ 08865-2764 (908) 859-2631 - - (908) 859-2875-FAX E-Mail: goldmrkr-at-fast.net/goldmarker-at-aol.com Web Page: http://members.aol.com/goldmarker
~~~"Goldmarking is everlasting probing!"~~~ ********************************************************
About a month ago I asked for experiences with allergy experiences when using acrylate embedding media. This is the third series..
9) I have personal experience with methyl methacrylate contact allergies. Years ago, when I was taught how to embed and section JB-4 (from Polyscienses), I was told that the solutions could cause a poison ivy-like reaction if I got it on my skin. My teacher, however chose not to were gloves, so neither did I. After a couple of months of continuous use, I developed the worst reaction that you could imagine. The fingers that had been in contact with the liquid form of the acrylic started to itch and burn, deep inside the flesh. Next, my fingers swelled to the size of a meaty hotdog and itched like crazy. Any attempt to even touch then sent sharp pains through my hand. I took antihistamines as soon as the reaction started and applied ointment for two days before the reaction was over. After that episode, I accidently touched the solid form once or twice and scrubbed my hands immediately and at length And took some more antihistamines. Still, I got a minor reaction that lasted a day each time. Now, about 10 years later, I still use JB-4 for alot of our samples, but I Always were gloves, and glasses when I'm arround it and I always wipe down work surfaces when I'm finished for the day. I have not had another even minor reaction for at least the last 5 years and never one as bad as the first. The reactions to these acrylics can be quite painfull, but many of the other embedding medias available are carcinogenic, with no early warnings. At least with this material, I know immediately when I've gotten too careless with my safety precautions.
Karen Pawlowski
10) i do not recall her name off hand, but if you contact rmc,inc tucson,arizona,(they probably have a web page) and ask who was their biological instructor at their ultra microtomy conference this year in oct . I specifically remember, and i was surprised that she repeatedly cautioned the group about similar severe allergy-proned individual-reactions being rather common. I believe she also may be linked to this newsgroup and may reply directly. i believe she was retired and now consulting from her home in the Stanford area. when i can get to my records i'll try to remember to recover her name and send her e-mail address. i'm quite bad with names.
Charles J. Day
---------
Regards, Don Cox ******************************************************** Donald P. Cox, Ph.D., M.B.A. GOLDMARK BIOLOGICALS/D.P. COX ASSOCIATES 437 Lock Street, Phillipsburg, NJ 08865-2764 (908) 859-2631 - - (908) 859-2875-FAX E-Mail: goldmrkr-at-fast.net/goldmarker-at-aol.com Web Page: http://members.aol.com/goldmarker
~~~"Goldmarking is everlasting probing!"~~~ ********************************************************
I had difficulty forwarding a very helpful response from Stephen Griffiths and if it does not go this time I will re-write it....
5) Hi Don
I have certainly had contact dermatitis from use of Lowicryl K4M. Not an allergic reaction though.
I discovered, after using K4M with latex or plastic gloves for several years that Lowicryl penetrates within a few minutes. There are a couple of papers, I've no doubt you are familiar with them, which dealt with the subject. They were primarily concerned with "pushing" 4H Gloves but still interesting for all that.
I have the papers somewhere but couldn't put my hands to them, so I found the Refs from BIDS, which follow (I think this is technically a breach of their copyright, but it saves me digging around in boxes for an hour)
**************************************************************************** **************** 1) TI: A GLOVE WITH EXCEPTIONAL PROTECTIVE FEATURES MINIMIZES THE RISKS OF WORKING WITH HAZARDOUS CHEMICALS AU: TOBLER_M, FREIBURGHAUS_AU NA: UNIV HOSP ZURICH,DEPT INTERNAL MED,H LAB 8,CH-8091 ZURICH,SWITZERLAND JN: CONTACT DERMATITIS, 1992, Vol.26, No.5, pp.299-303
2) TI: EXCEPTIONAL PROTECTIVE POWER OF THE 4H GLOVE DEFEATS OCCUPATIONAL RISKS IN ELECTRON-MICROSCOPY AU: TOBLER_M, FREIBURGHAUS_AU NA: UNIV SPITAL ZURICH,DEPT INNERE MED,H LAB 8,CH-8091 ZURICH,SWITZERLAND JN: JOURNAL OF MICROSCOPY-OXFORD, 1991, Vol.163, No.JUL, pp.RP 1-RP 2
There is this problem, that using gloves gives a sense of false security. But the above papers show that penetration occurs very rapidly with ordinary gloves.
My problem may have arisen from handling improperly polymerised blocks without gloves during sectioning. The pattern of the dermatitis would seem to be consistent with that.
I tried 4H gloves. They were doubtless very effective, but difficult if you were handling small blocks and BEEM capsules. 4H gloves are a bit like wearing Aluminium foil. Not exactly sensitive!
If your customer absolutely HAS to use acrylics then s/he may find 4H gloves of some use. Though if it is a real full blown reaction the best thing they can do is avoid it at all costs, 4H gloves or no 4H gloves.
Eczema or contact dermatitis seems to be the favourite reaction to acrylics. I don't have to use them at the moment and the condition of my fingers has improved after three years. However once you get this sort of thing it never really goes away and can be triggered by agents other than the original one.
This can have its benefits occasionally as it gets me out of the washing up at home when I am having a recurrence of the condition. ;)
Regards Stephen Griffiths
AND FINALLY..... 14) It would be nice if you'd summarize and post the information you might receive on this subject. Safety in the laboratory is so important and people don't always realize (or remember) that. Thank you very much in advance. Adriana
-------------
Whew! That's over...!
Regards, Don ******************************************************** Donald P. Cox, Ph.D., M.B.A. GOLDMARK BIOLOGICALS/D.P. COX ASSOCIATES 437 Lock Street, Phillipsburg, NJ 08865-2764 (908) 859-2631 - - (908) 859-2875-FAX E-Mail: goldmrkr-at-fast.net/goldmarker-at-aol.com Web Page: http://members.aol.com/goldmarker
~~~"Goldmarking is everlasting probing!"~~~ ********************************************************
For your short term problem, get a "Snappy" frame grabber. Cheap but quality per $ spent is very very good. It's also very simple to use, just plug it into your paralell port.
Check out this site: http://www.zdnet.com/pccomp/sneakpeeks/snpk1096/snappy.html
That price for a dual Pentium system seems a bit high. The machine I'm using now, I put together as a motherboard and hard drive upgrade to a Gateway 486. It is a dual Pentium (133) PCI-EISA board with 512 K pipelined burst cache and 32 megs of RAM. Nothing around here can touch it in terms of speed and performance. Price of the upgrade (which I did myself): about $3200, including Windows NT to support the dual processor.
-=W.L. Steffens=- Department of Veterinary Pathology College of Veterinary Medicine University of Georgia
I use a commercial program from a company in your home town of Bochum, Germany. See their web site at www.tech-inter.com phone +49 234 30 96 96. The program's name is PicDoc. best regards mark
Mark W. Lund, PhD Director } } Soft X-ray Web page http://www.moxtek.com { { MOXTEK, Inc. ************************************************* Orem UT 84057 **"Soft x-rays in the 21st Century" conference ** 801-225-0930 ** 8-11 January 1997, Midway Utah ** FAX 801-221-1121 ** http://volta.byu.edu/xray/info.html ** lundm-at-xray.byu.edu *************************************************
"Let me commend a great truth to you which has been one of the supports of my life: 'The Gods send threads for a web begun.' Andrew Carnegie
Back in December I asked what X-Y-Z stage controllers were out there for an inverted scope & mac compatable.
Here's a summary of the replies...
Signal Analytics Vienna, VA 703-281-3277 $13k ***************************** New England Affiliated Technologies 620 Essex St. Lawrence, MA 01841 Tel 508-685-4900 or 800-227-1066 Fax 508-688-8027 $5k ***************************** Prior Scientific, 800-877-2234 $13k ***************************** thanks to all who helped.
I am interested in fluorescence imaging of single cells. However, these = cells will be in suspension. The medium will be quiescent and I want to = disturb the cells as little as possible. To that end, does there exist = a dye or a technique whereby the dye does not need to be rinsed from the = medium? =20
Are there other possibilities, such as a fluorescent dye that is = effective more than a couple hours after the cells have taken it up, or = slow release of the dye from beads, etc?
I will most likely be doing calcium measurements on mammalian bone or = smooth muscle cells.
Hello, I was wondering if anyone read the article about SGI's O2 system in the Jan 97 issue of BYTE. It compares the single processor O2 to a dual 200MHz Pentium Pro. The price of the tested SGI was $8342 while the price of the tested Pentium was $11,432. The article also quotes that O2 starting prices are below $6000.
The O2 model they wrote about had 128Mb of RAM, 2 2-Gb hard drives, and a 180MHz clock. The dual Pentium model also had an extra 16Mb of something called "Intense 3D".
The artice compared OpenGl performance. The dual Pentium performance was only slightly better (for $4000 more). I wonder about floating point operations though. I would be surprised if the dual Pentium could perform more quickly in that area, based on the Pentium Pro and R5000 (O2's CPU) floating point specifications I've seen/heard.
I'm wondering what the microscopy community's views are on the PC vs. UNIX (SGI specifically) issue. Or does anyone have anymore information on this topic?
Personally, I was really surprised by the article in BYTE even though it's only an OpenGl comparison. I had heard about how the dual Pentium Pro's were going to blow the SGI's out of the water and at a cheaper price. The hardware alone that is being bundled with this SGI was a shock given past SGI prices I've seen (in an academic setting).
We want to start with image analyzation andhave no idea about it, yet. What we have is a Zeiss Axioplan microscope with a Sony CCD camera (DXC-101P) attached to it. It has a resolution of 320x350 lines. There is also a photo camera for slides and negatives.
We need to measure areas in light microscopical sliceseither manually and automatically by their grey values. An option for 3D reconstruction would be nice, too.
My questions are now: 1) What further equipment do we need (frame grabber? better (digital?) camera? PC, MAC, workstation?)
2) Which software do we need? (what makes the difference between shareware (e.g. NIH Image) and expensive programmes to buy for some k$?
3) Is it worth to buy a commercial available complete system?
These questions may be very basic so possibly there is a site to look for FAQ like this. Which newsgroups cover this topic?
Any suggestions are welcome.
Hans-Martin
************************************************************** Hans-Martin Vaihinger Ruhr-University of Bochum Comparative Endocrinology Research Section Building ND 5/37 44780 Bochum GERMANY ********************************************************* phone ++49 234 700 4329 fax ++49 234 709 4551 email Hans-Martin.Vaihinger-at-RZ.Ruhr-Uni-Bochum.de
There was also a report about a no-nonsense new Motorola chip, the X704, which would be a 530 MHz puppy to be fitted into the next generation MACS. Maybe we can go back to user-friendly systems with excellent performance... Windows just doesn't quite cut it yet.
} X704, which would be a 530 MHz puppy to be fitted into the next What would the cost of a system with that kind of chip, the data bus of an SGI, and the rest of the accessories be like?
} That price for a dual Pentium system seems a bit high. The machine } I'm using now, I put together as a motherboard and hard drive upgrade } to a Gateway 486. It is a dual Pentium (133) PCI-EISA board with 512
Are those Pentium Pro chips? That's what they were looking at in the article I read.
--IMA.Boundary.541876258 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Description: cc:Mail note part
I would like to thank Don for posting replies to his query about sensitivity to acrylics. No, Don, it shouldn't be "Whew! That's over...!" (I know what you mean), for anyone in the microscopy field who is exposed to chemicals, radiation, and/or any other hazard - it should be just the beginning!. I would ask everyone to consider that we do no know what the long term effects of exposure to many individual chemicals or combinations of chemicals can have on your health. Are you willing to risk a terminal illness when it is relatively easy for you can work in a fume hood and wear personal protective gear? I would hope not!
------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America
I had difficulty forwarding a very helpful response from Stephen Griffiths and if it does not go this time I will re-write it....
5) Hi Don
I have certainly had contact dermatitis from use of Lowicryl K4M. Not an allergic reaction though.
I discovered, after using K4M with latex or plastic gloves for several years that Lowicryl penetrates within a few minutes. There are a couple of papers, I've no doubt you are familiar with them, which dealt with the subject. They were primarily concerned with "pushing" 4H Gloves but still interesting for all that.
I have the papers somewhere but couldn't put my hands to them, so I found the Refs from BIDS, which follow (I think this is technically a breach of their copyright, but it saves me digging around in boxes for an hour)
**************************************************************************** **************** 1) TI: A GLOVE WITH EXCEPTIONAL PROTECTIVE FEATURES MINIMIZES THE RISKS OF WORKING WITH HAZARDOUS CHEMICALS AU: TOBLER_M, FREIBURGHAUS_AU NA: UNIV HOSP ZURICH,DEPT INTERNAL MED,H LAB 8,CH-8091 ZURICH,SWITZERLAND JN: CONTACT DERMATITIS, 1992, Vol.26, No.5, pp.299-303
2) TI: EXCEPTIONAL PROTECTIVE POWER OF THE 4H GLOVE DEFEATS OCCUPATIONAL RISKS IN ELECTRON-MICROSCOPY AU: TOBLER_M, FREIBURGHAUS_AU NA: UNIV SPITAL ZURICH,DEPT INNERE MED,H LAB 8,CH-8091 ZURICH,SWITZERLAND JN: JOURNAL OF MICROSCOPY-OXFORD, 1991, Vol.163, No.JUL, pp.RP 1-RP 2
There is this problem, that using gloves gives a sense of false security. But the above papers show that penetration occurs very rapidly with ordinary gloves.
My problem may have arisen from handling improperly polymerised blocks without gloves during sectioning. The pattern of the dermatitis would seem to be consistent with that.
I tried 4H gloves. They were doubtless very effective, but difficult if you were handling small blocks and BEEM capsules. 4H gloves are a bit like wearing Aluminium foil. Not exactly sensitive!
If your customer absolutely HAS to use acrylics then s/he may find 4H gloves of some use. Though if it is a real full blown reaction the best thing they can do is avoid it at all costs, 4H gloves or no 4H gloves.
Eczema or contact dermatitis seems to be the favourite reaction to acrylics. I don't have to use them at the moment and the condition of my fingers has improved after three years. However once you get this sort of thing it never really goes away and can be triggered by agents other than the original one.
This can have its benefits occasionally as it gets me out of the washing up at home when I am having a recurrence of the condition. ;)
Regards Stephen Griffiths
AND FINALLY..... 14) It would be nice if you'd summarize and post the information you might receive on this subject. Safety in the laboratory is so important and people don't always realize (or remember) that. Thank you very much in advance. Adriana
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Whew! That's over...!
Regards, Don ******************************************************** Donald P. Cox, Ph.D., M.B.A. GOLDMARK BIOLOGICALS/D.P. COX ASSOCIATES 437 Lock Street, Phillipsburg, NJ 08865-2764 (908) 859-2631 - - (908) 859-2875-FAX E-Mail: goldmrkr-at-fast.net/goldmarker-at-aol.com Web Page: http://members.aol.com/goldmarker
~~~"Goldmarking is everlasting probing!"~~~ ********************************************************
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Seeing the recent posting re Balzers Electron Beam Gun power supply prompts me to ask this: I run a 25-year-old JEOL microprobe, with very little chance of ever getting funds to buy a new replacement. One of these days the HV and gun filament supply (which uses vacuum tubes, including, for all the old-timers, a type 807!!!) is going to up and die, possibly by catastrophe within the tank. Are there available 3rd-party supplies which I could just graft in (maybe necessitating the fabrication of a custom cable) in that event? Is that what the aforementioned Balzers thingummy is? Anybody got an address for them or for anyone else who makes this sort of thing?
Happy New Year
Ritchie
Ritchie Sims phone: 64 9 3737599 ext 7713 Department of Geology fax: 64 9 3737435 University of Auckland Private Bag 92019 Auckland New Zealand
Thanks to all who responded to my request about image capture systems. I have included a sanitized version of all the responses (I removed most vendors names and the like). I have all the original posts so email me if anything catches your eye and you need more particulars.
Bob Wise UW-Oshkosh
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I maintain an archive of most of the biologically relavant postings to this list. You are correct that this has been a hot topic in the last few months and I have archive it at our web site. Go to the URL listed at the end of this message and click on the "Tips & Tricks" link. Within there you will find a section on "Computers" Look at the section titles "Acquiring Digital Images". Let me know and I can get you the info in some other way if you need. http://www.biotech.ufl.edu/~emcl/
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We also have the Hitachi/Quartz PCI imaging system. I recall it being pricey, but we have been satisfied with it. It takes some learning, but is rather easy to use. It does annotation, some measurements, databases of sessions, etc. And they allow (even encourage) us to freely distribute their viewer software. Even though it is of limited capability, it still does quite a bit.
We do most of our output on a HP 4M Laserjet. At times we wish for better grayscale rendition. But the PCI allows us to send our images back to the scope's Polaroid camera if we need to.
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We use ImageSlave capture boards which we have fitted to each of our 6 microscopes. They fit in a standard slot in any old PC. They can run in Windows, but we run ours in DOS. Its so simple. Every time you push the PHOTO button, the image going to the photo display gets digitised ( putting in a film is an option, now uncommon with us). All you need to do is give a filename and the picture is saved to disk. The images are 1024x 1024 x 256 which we find perfectly good enough for our work. They are US $5,000 including software.
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One system that I think you ought to take a close look at is SEMICAPS. In 1990, I had one interfaced to my (then) Cambridge S200 SEM and I was very pleased with the results. At that time, I was also quite impressed by the customer service elicited by SEMICAPS. I have since moved this system to my light microscope for image analysis purposes. The SEM now has a new Link ISIS EDS system which has its own imaging capability. I am sure that the new SEMICAPS systems are even better, and I would hope that the customer service is still world class.
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The PCI system we sell is easily installed and very easy to learn how to use.
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We are looking into representing a company that makes a powerful, yet relatively inexpensive PC-based active system that includes the control board and software, and we can certainly configure it with a PC. We have access to a passive acq. system also, but I do not yet have much detail on this one. If you are interested, please feel free to contact me. We also represent a company who makes a versatile SW product for digital image archive and databasing, thumbnail viewer, etc. I'd be happy to discuss these and our new Image Analysis SW, Visilog in more detail, if you are interested.
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I am in a similar position of trying to set up an image capture system from our SEM also. I have just taken a work transfer, and have the challenge of setting up an EM/imaging facility where there was none before. Lots of fun, and something new for me, although I have spent almost 20 years doing EM, I have never actually been responsible for setting up or running the lab!!
I am starting to investigate options to get this system set up. It seems that we already have an image analysis software package (SigmaScan Pro from Jandel) and a fancy Pentium to run it on. In terms of the actual capture system for the SEM, I have heard from a number of my colleagues that the Hitachi PCI system is the best one out there, in their opinion. It is an entire system, including the computer, which can be augmented to be used with LM and TEM (for more money of course). It is expensive ($12.5K CAN) but is apparently worth every penny (we couldn't afford it). Another company in the US (4pi) sells a PCI system for quite a bit less money, but you have to supply your own Pentium or Mac computer. Then there is another approach, which was suggested by John Mackenzie (North Carolina State University) at one of the courses he gave, called a "gated Integrator", - I'm not sure of the company who sells these, but I plan to contact him to find out.
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I have seen your request for digital image capture (with annotation, file storage, printer etc.). We have just such a system that does all that and some more. We have developed it ourselves and it runs our Hitachi 2300. It has the features you list plus automatic contrast setting, image averaging and is also used with our EDX to obtain element maps. It also captures images from several of our other instruments (Auger and SIMS systems). If you are interested I could send you a demo either by email or on a floppy.
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We purchased an Hitachi S3200N variable pressure SEM early this year and have the Quartz PCI system that they sell. It runs on a PC and since I had been a Mac person up until this I had to learn a few new tricks. With windows 95 it was not difficult to get going after a short time. This system only captures images at the photo scan rate so you sit for the same length of time it takes to expose a Polaroid. You can do both at the same time. One thing we don't have yet is the option to "play back" a stored image to the microscopes polaroid camera. We will get this soon. Once the image is captured it is composed of two files, the image file in the TIF format, or you can chose from a list of others, and a text file containing any text associated with the image. It lets you put labels and arrows and do some measurments. You can also rotate things and crop images. It does probably most things one needs. It works like some of the drawing or graphing programs such as Cricket graph or MacDraw. Any labels or text can be permenantly "burned into" the image but can not be changed once this is done. This is somewhat important since when you export the image file the text file must also go along unless it is "burned in". We do work for a variety of users and they may not always like where or the type of label applied. This is a minor logistical problem but a pain in the butt with some of our more "difficult" customers. One odd thing is that the information bar, with micron marker, at the bottom of the image and any labels or text added to the image on the microscope (the 3200 lets you label and measure on its screen, I don't know if your SEM does this) DO NOT capture very well. The characters are incomplete. This has something to do with the way the SEMs character generator produced the letters and figures. They show up fine on polaroids because during the film exposure all characters in the image field and info bar are exposed at the end of the scan. I think this scan is repeated several times to provide complete characters. The PCI system stops capturing once the scan reaches the bottom of the screen therefore the characters only get one pass and show up with some missing spots. I explained and showed this to our Hitachi service engineer and she had never noticed this before and was going to bring it to the attention of the PCI people. The characters that PCI generates are very nice and you can change the font and its size as well as bold or italics. It can store images as a database, which was too much for me, or like regular DOS files. I create a folder for each client and folders inside for various projects or samples from that client. A searchable database is nice but who has time time figure all that stuff out. I have not evaluated any other systems and can't comment on them. Over all the PCI system has met our needs but the problem described above is annoying.
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Saw your question on the microscopy listserver and since we have an Hitachi SEM (S-450LB) with a Quartz PCI frame grabber I thought I would respond with some comments. The system works very well for image capture and has considerable versatility. If you have a good service person for installation it can be set up in an afternoon. The biggest problem is getting the right computer box as the two boards are very large. We have a Certified Data pentium computer with four ISA slots and 3 PCI slots, and the boards just barely fit. Things like power supplies and fans can get in the way. My recommendation is to have Hitachi select the computer for you if you are going with this system. The data base associated with the frame grabber is quite powerful and allows a lot of manipulation of images for archiving and processing. It is not the most user-friendly system and I am still trying to figure it out. I have many fourth year undergraduate students using it this semester and teaching them how to run it has been rather frustrating. Once we develop a consistent methodology for storing images from a variety of student users, and write up our own manual things should go easier. The manual that comes with it is written for someone with a good working knowledge of computers, and should be scaled down for people like myself. I looked around for awhile before buying this unit and feel that it is probably the best passive capture system on the market, although the Orion system looks interesting as well and may be cheaper. As far as I can tell both systems do much the same thing, i.e. capture images at variable resolutions that are easily manipulated, and allow playback to the photo recording camera (a useful feature). I'm not sure whether the Orion system comes with a built in data base or whether you have to purchase a separate one. I hope this helps you and don't hesitate to write back with more questions if you have them.
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I used thdHitachi PCI system with my S-2500 and loved it. I don't think there is any other system that works as well.
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I have experience with the Hitachi system, which is actually made by Quartz Imaging and sold by Hitachi. It can be fitted after-market to any SEM of any make. I have two: one on a Hitachi S-570 (1985) and one on a Hitachi S-2300 (1990). The program, called PCI, runs under Windows 95 and takes any slow scan image into the computer where you can do anything with it you wish. I use it on 17-inch monitor, where it shows the image to a whole class like a 11" X 14" blowup. I print to a laser printer and have cut my Polaroid expenses to about one-third. Everyone likes the ability to put images into documents with "Edit-Copy", "Edit-Paste". There are other systems sold, I have seen them but not used them. GW has one, there is one from Australia and there is one from Europe. I'm sure others will tell you about them. I know it is hard to realize now, but after you have one you will wonder how you managed without.
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We sell the Orion system in this country. It, like the Hitach system, is a passive capture system. i.e. it sync's to the line and frame of the microscope and digitized the ouput signal. We have customers who have tried both systems and think that the Orion gives better (less pixel jitter, better S/N) images). The system can capture any size up to 8kx8k. It averages and integrates images to reduce noise. A complete system with 1200dpi printer on a 200MHz Pentium wiht 32 MG RAM sells for about $20,000. We can send you some sample images and lit if you are interested.
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DVC Company offers 10 bit real time analog and digital output CCD cameras with standard C mount for coupling, and many different frame grabber boards and software as a system.
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Bob - you can get information about the Orion system off of the web at http:\\www.microscop-uk.org.uk,80/prodir/orion1.html
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I had a demostration of PCI image system from Hitachi at my E.M. Unit a year ago. I was quiet impressed about how easy to capture the image from my Hitachi S-2500 SEM and replay back to camera for photo quality picture. Now acturally I just purchased the sytem a week ago. I played around a bit and found it is even better than what I thought. In the version 4 of the system , it is more easy to get 3-D image and color the images capatured from SEM. I plan to introduce it to my clients to use it as daily research and get instant images on printer or store in a zip drive 100 MB disk in the new year.
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E. Fjeld also is a distributor of the SEMICAPS (PC) imaging system. Another board, DIGISEM, is also available fron the ELMDAS Co. in Alexandria PA. Contact John Best at:
A third option is the 4PI system. They now offer both MAC and PC. Contact Mike Czysz at:
4pi Analysis, Inc. 3500 Westgate Drive, Suite 403 Durham, North Carolina 27707-2534 (919) 489-1757 http://www.4pi.com czysz-at-4pi.com (I think) **************
} I would like to thank Don for posting replies to his query about } sensitivity to acrylics. No, Don, it shouldn't be "Whew! That's } over...!" (I know what you mean), for anyone in the microscopy field } who is exposed to chemicals, radiation, and/or any other hazard - it } should be just the beginning!. I would ask everyone to consider that } we do no know what the long term effects of exposure to many } individual chemicals or combinations of chemicals can have on your } health. Are you willing to risk a terminal illness when it is } relatively easy for you can work in a fume hood and wear personal } protective gear? I would hope not! } } Damian Neuberger
Has anyone done an epidemiological survey on life expectencies and causes of death (besides frustration) of microscopists? Life vs Materials? Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Microscopy Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
CAN SOME ONE TELL ME , DOES A 530MHz PUPPY HAVE A BYTE ?
HAPPY NEW YEAR
Patrick Echlin Multi-Imaging Centre CambridgeOn Tue, 7 Jan 1997, Nathan O'Connor wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } } X704, which would be a 530 MHz puppy to be fitted into the next } What would the cost of a system with that kind of chip, the data bus of an SGI, } and the rest of the accessories be like? } } Nathan }
} Are those Pentium Pro chips? That's what they were looking at in the article I } read.
Nathan,
The motherboard that I purchased supports Pentium Pro chips, but out of economics, and at that time a scarcity in that chip, I elected to go the cheaper route. I'll eventually upgrade to the superfast chips when the price goes down, but for the time being, this system is more than adequate for my needs.
-=W.L. Steffens=- Department of Veterinary Pathology College of Veterinary Medicine University of Georgia http://www.vet.uga.edu/wls/steffens.html
Can anyone tell me a good way to quantify Pb concentration in a "galvanized" coating on steel. My understanding is that Pb is distributed in the coating such that focused micro beam techniques may have difficulty sampling enough territory to be accurate. We have SEM/EDS, AES, EPMA, XRF and ICP here in the lab.
Any "tricks" or experience on this matter would be greatly appreciated.
thanks Terry R. McCue Babcock & Wilcox Research 1562 Beeson St. Alliance, Ohio 44601 Phone: 330-829-7427 Internet: terry.r.mccue-at-mcdermott.com Fax: 330-829-7831
Tina, I saw Mary Mager's comments about rapid (TV) scan giving a poor image from an SEM. She is right, because the signal-to-noise is much worse at TV rates. Now, I have a question. Actually, three questions. (1) Would it be possible to collect several successive images at TV rates and average them to improve the signal-to-noise, and thereby obtain a decent image? (2) Can this be done with a SNAPPY frame-grabber? (3) Is there software which will do this? Dr. Dennis B. Barr | 333 DDDDD 333 DDDDD Eastman Chemical Company | 3 3 D D 3 3 D D Microscopy and Morphology | 3 D D 3 D D Research Laboratory | 33 D D 33 D D P.O. Box 1972 | 3 D D 3 D D Kingsport, TN 37662-5150 | 3 3 D D 3 3 D D | 333 DDDDD 333 DDDDD Voice: 423/229-2188 | E-mail: dennbarr-at-eastman.com | IMAGE IMAGE FAX: 423/229-4558 |----------------------------------------------------- (Cross your eyes to see the 3 dimensional image above)
} Now, I have a question. Actually, three questions. (1) Would it be } possible to collect several successive images at TV rates and average them } to improve the signal-to-noise, and thereby obtain a decent image?
Yes, we do this with our video-rate intensified CCD. We can also do a background subtraction, running average, exponential fall-off average and other processing.
} (2) Can } this be done with a SNAPPY frame-grabber?
I don't know. Most, if not all, our capabilities are built into the Perceptics PixelTools 425 Series video capture board.
} (3) Is there software which will } do this?
NIH Image and others can do the processing. The real-time display of the processed images at video rates, however, is more difficult. The Perceptics board does this in our application. I don't know whether the combination of hardware you want and some processing software can do this. Yours, Bill Tivol
------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Reply to: RE} } Sgi and Pentium Pro, also MAC??!!
} Date: 1/7/97 1:48 PM } From: jan ringnalda
} There was also a report about a no-nonsense new Motorola chip, the } X704, which would be a 530 MHz puppy to be fitted into the next } generation MACS. Maybe we can go back to user-friendly systems with } excellent performance... Windows just doesn't quite cut it yet.
} Cheers, Jan
Thanks Jan,
I was about to spend my money on a mere 500MHz DEC Alpha running Windows NTwith 512MB RAM, 4.3GB fast-wide SCSI disk and 21" 0.25mm 1600x1200 monitor . . .
One of my zip disk which contains important data was unreadable. The zip drive is working all right. I tried to call the Iomega com. but they are hard to reach. Is anyone has experience on this type of problem? Is any way I can recover some of my data files? Thank you.
**************************** * Maoxu Qian, Ph.D. * * Dept of MSE, box 352120 * * University of Washington * * mxq-at-u.washington.edu * * (206)543-1514(phone) * * (206)543-3100(fax) * ****************************
I just checked prices of the dual pentium pro systems available from Micron Electronics. Systems with 2 200Mhz processors can be had from about $3500 and their most expensive configuration is about $7500. The upgrade to the second processor from a single processor system is $700. Obviously there are graphics workstations available with more capabilities and higher prices (probably including the system compared in BYTE). I checked the prices from Micron because I own a couple of their computers. If you want more info on similar systems I suggest you take a look at Intel's web site. They have links to a number of companies that sell such systems. Mike
Mike Bench Characterization Facility Center for Interfacial Engineering University of Minnesota Voice: (612) 624-6590 Fax: (612) 626-7530 e-mail: bench-at-cems.umn.edu
I just checked prices of the dual pentium pro systems available from Micron Electronics. Systems with 2 200Mhz processors can be had from about $3500 and their most expensive configuration is about $7500. The upgrade to the second processor from a single processor system is $700. Obviously there are graphics workstations available with more capabilities and higher prices (probably including the system compared in BYTE). I checked the prices from Micron because I own a couple of their computers. If you want more info on similar systems I suggest you take a look at Intel's web site. They have links to a number of companies that sell such systems. Mike
Mike Bench Characterization Facility Center for Interfacial Engineering University of Minnesota Voice: (612) 624-6590 Fax: (612) 626-7530 e-mail: bench-at-cems.umn.edu
I embedded tissue culture cells on glass coverslips in EMBed (Epon-like) and now cannot remove the glass with thermal or mechanical shock.Please let me know if you have a trick for separating glass from epoxy without destroying the epoxy. I also have experiments running with plastic substrates but would like to recover this one sample. Note: the coverslips were coated only with poly-D-lysine and embedded by inverting a Beem capsule filled with epoxy on the coverslip. Thanks! Larry D. Ackerman (415) 476-8751 Howard Hughes Medical Institute FAX (415) 476-5774 UCSF, Box 0724, Rm U426 533 Parnassus Ave. mishot-at-itsa.ucsf.edu San Francisco, CA 94143
------------ Forwarded Message begins here ------------
Hi, there,
Several people asked me more information on the problem. Sorry I didn't say clearly. This is on a MacIIci mation, When insert the zip disk, it keeps rotating then a click sound and rotating and click sound ...for long time and in the end, the message cames out as "unreadable disk". I tried use Norton utility to recover it but Norton did not recognize zip drive. Is there any utility software can do it? or the disk is physical damaged? The disk was sitting inside of the drive all the time but due to reboot, I have to reinsert it and the problem occurred. Any suggestion? Thank you again.
**************************** * Maoxu Qian, Ph.D. * * Dept of MSE, box 352120 * * University of Washington * * mxq-at-u.washington.edu * * (206)543-1514(phone) * * (206)543-3100(fax) * ****************************
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } I embedded tissue culture cells on glass coverslips in EMBed (Epon-like) and } now cannot remove the glass with thermal or mechanical shock.Please let me } know if you have a trick for separating glass from epoxy without destroying } the epoxy. I also have experiments running with plastic substrates but would } like to recover this one sample. Note: the coverslips were coated only with } poly-D-lysine and embedded by inverting a Beem capsule filled with epoxy on } the coverslip. Thanks! } Larry D. Ackerman (415) 476-8751 } Howard Hughes Medical Institute FAX (415) 476-5774 } UCSF, Box 0724, Rm U426 } 533 Parnassus Ave. mishot-at-itsa.ucsf.edu } San Francisco, CA 94143 } } Larry --
Our method of last resort is to jam the tip of a dissecting needle under an exposed edge of the coverslip, then pry up gently trying to lift the the coverslip off of a near-by region. You end up damaging some of the specimen this way, but with some luck and careful trimming at the microtome one can still get some nice areas to section.
Hope this helps, Greg Martin Dept. of Cell Biology and Anatomy Johns Hopkins School of Medicine
At 10:16 AM 1/8/97 -0500, you wrote: } Can anyone tell me a good way to quantify Pb concentration in a } "galvanized" coating on steel. My understanding is that Pb is } distributed in the coating such that focused micro beam techniques may } have difficulty sampling enough territory to be accurate. We have } SEM/EDS, AES, EPMA, XRF and ICP here in the lab. Dear Terry, My recommendation would be EPMA with a de-focused beam. Spread the beam to 2 to 5 microns in diameter and sample at least 10 random spots. Be sure to test the substrate element (i.e. Fe) to track differences in coating thickness, which will affect apparent Pb concentration. A known standard would also be very helpful. Good luck, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
} Now, I have a question. Actually, three questions. (1) Would it be } possible to collect several successive images at TV rates and average them } to improve the signal-to-noise, and thereby obtain a decent image? (2) Can } this be done with a SNAPPY frame-grabber? (3) Is there software which will } do this? Dear Dennis, Yes, some frame-grabbers can do frame averaging on several successive frames (I have seen up to six). This is a hardware characteristic of the more expensive frame grabbers. The TV rate is too fast for software. I don't think the Snappy has this characteristic. The image must be stable, which TV rate images on SEM sometimes aren't,a nd of course the resolution will be limited to the 525 lines of NTSC. I think the Snappy would be a good Light Microscope solution, but less so for SEM. Good luck, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
At 12:59 PM 1/8/97 -0800, Larry Ackerman wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Larry, Have you tried cooling the glass coverslips on the surface of a piece of dry ice? It (the coverslip) usually pops off leaving the embedded cells behind. Rosemary
Seasons greetings to TEMists, SEMists & probers. We at the University of Durban-Westville are planning to purchase a new TEM in the near future. YThe machines under consideration at the moment are the Philips 208S or if finances permit Jeol 1010.
To assist with our selection, I would appreciate responses from any of you with experiences (good or bad) with either instrument. Particular areas of interest are: 1. Quality control and reliability of electronic and mechanical components. 2. Quality of images at all maginifications and instrument stability.
We are replacing a still functional Philips 301 - any offers!
To avoid cluttering up the list, please contact me at my e-mail address.
Best wishes for 1997
Mike Gregory EM Unit University of Durban-Westville Durban South Africa
I would appreciate suggestions for examining 80 micron eggs in seawater or distilled water by SEM where the user wants to compare fresh egg surfaces (therefore cryo?) with conventionally fixed, dehydrated and critically point dried eggs.
The idea was to use cryoSEM but there are problems. I have tried freezing (in ethane) on a thin smear of Tissue Tek OCT - droplet on stub and then wiped off with cover slip (not easy in itself?), but the eggs sank, never to be seen again!
I have also frozen them just mounted in a water film, but some have simply sheared off the standard smooth stub - should I try poly-L-lysine or super glue?
A separate problem seems to be that while the crustacean in question is marine/estuarine and the eggs stand fresh water for a while (therefore for rinsing), even after 3 or 4 distilled water changes I still see a fine, dried layer of salt over everything. The rinsing is done in a watchglass and the water was almost completely removed with an autopipette before refilling.
One idea not tried yet is to place an egg on a millipore filter, drain on filter paper, place on stub in cryoSEM airlock cold-stage and freeze in situ. But with or without vacuum?
It seems a crazy world when it is easier to ask internet friends than it is to search through a bucket a mud and then do the experiments on the method to use!
Any comments would be appreciated. Take up gardening?
Thanks in advance - Keith Ryan
++++++++++++++++++++++++++++++++++++++++++++++++++ Plymouth Marine Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, England
e-mail: k.ryan-at-pml.ac.uk PML web site: http://www.npm.ac.uk/pml ++++++++++++++++++++++++++++++++++++++++++++++++++
One method we use to remove the glass coverslip is to place the block with the attached coverslip into hydrofluoric acid. The acid will slowly dissolve the glass in about an hour. The acid does not dissolve epoxy, and we have not noticed with the embedded cells.
Regards,
John J. Turek, Ph.D. Purdue University Dept. of Basic Medical Sciences Director, Core Laboratory for Image Analysis and Multidimensional Applications (CRISTAL) phone: 317-494-5854 fax: 317-494-0781 email: jjt-at-vet.purdue.edu web: http://vet.purdue.edu/cristal
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Hello to all~ I have recently joined this list, and found all of the discussion very informative. Since many questions discussed here deal with finding suppliers, I thought I would let you know of ASM International's online version of our "testing buyer's guide". It can be found at http://www.asm-intl.org/testing
The site gives contact details for over 400 companies providing services related to testing, including microscopy.It is based on information compiled by the editors of Advanced Materials & Processes, ASM's monthly magazine.
Best wishes for 1997~
Leslie H. Chom LHChom-at-po.asm-intl.org Information that Goes to Work-from the Materials Information Society ASM International http://www.asm-intl.org (ph) 216-338-5151 Ext 510 (fx) 216-338-4634
Greetings, and best wishes for the New Year. Volume 2, Number 1, of the PENSEES NOUVELLES is now on line at
http://www.emory.edu/PATHOLOGY/PENSEES
Contents include some medical doggerel, two book reviews (one about histologic techniques with microwaving, and one on golf), and the continuation of the review of the Robert Trent Jones Golf Trail courses.
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To look at surfaces of small samples, roughening the stub surface with fine sandpaper will help keep the ice on the stub during cryo, but we went into overkill and machined a slight "well" in the surface of the stub and then roughed it up. To get a cross sectional view, we drill several small wells (1/16 in.dia x 1/8 in. deep) in the stub. Overfill the wells (this can be tricky) with a high concentraion of sample in water leaving a slight droplet (protruding meniscus) of sample protruding above the well. Sometimes a little vaseline on the surface will help keep the droplets from running together. Freeze and shear off the droplets.
For the dry eggs, we would use about a dozen (pelco #16079) adhesive tabs stuck on the surface of a clean glass slide. Dissolve these into 20 ml chloroform. Place a drop or two of this solution on the surface of the stub (or coverslip for a smoother background surface), spread evenly and drain the excess with the corner of a kimwipe. This usually produces a very thin layer of adhesive strong enough for samples up to a few hundred microns.
As for the salt on the surface after 3 or 4 washes, not much help I'm afraid, just a thought. Is there a mucosal surface layer that the distilled water is drawing the salt out of ?? If so, they might need an EDTA treatment first to remove mucus. Then again, this mucus might be the surface you need to see??? This might be a case of "a rock and a hard place", but sucessful cryo should tell you what is on the surface if you can get a fracture through an egg.
Hope this is helpful.
Cheers :) George Department of Earth and Atmospheric Sciences University of Alberta Edmonton, Alberta T6G 2E3 Canada ph: 403-492-5746 fax: 403-492-2030
} Hi, there, } } Several people asked me more information on the problem. Sorry I } didn't say clearly. This is on a MacIIci mation, When insert the zip disk, } it keeps rotating then a click sound and rotating and click sound ...for } long time and in the end, the message cames out as "unreadable disk". I } tried use Norton utility to recover it but Norton did not recognize zip } drive. Is there any utility software can do it? or the disk is physical } damaged? The disk was sitting inside of the drive all the time but due to } reboot, I have to reinsert it and the problem occurred. Any suggestion? } Thank you again. }
Maoxu,
Rebooting after computer crash can damage the important directory/b-tree area on disk. I do have experience of this kind of damage. The damage didn't recover by Norton Utility. Now I always take the disk out before rebooting. After rebooting, insert and eject it, then insert it again. Now it works normally.
Ya Chen
Ya Chen
*** My email address has been changed to: ychen14-at-facstaff.wisc.edu *** ========================================================================= \ / Integrated Microscopy Resource (IMR)--
\ / __ an NIH Biomedical Research Resource TEL : 608-263-8481 \/ / / University of Wisconsin-Madison FAX : 608-265-4076 / / / 1675 Observatory Drive #159 Email1:ychen14-at-facstaff.wisc.edu / /__/_ Madison, WI 53706 Email2:chen-at-calshp.cals.wisc.edu ========================================================================= IMR WWW Home Page: http://www.bocklabs.wisc.edu/imr.html
I agree wholeheartedly with Mary Mager on the suitability of Snappy for SEM. I'd only recommend them in two cases, as I've discussed with some of you privately.
1. Where there is absolutely no money for a better solution AND the user has lots of time to attempt offline averaging solutions AND the samples aren't very demanding.
2. Where the SEM has built in frame averaging capability AND the only application for the instrument is simple photographic documentation.
I think Tina fits into catagory one. I'm basing this partially on the images at her website. If a large percentage of her work is at very low magnification, stability becomes less of an issue and she has the possibility to average images off-line.
Dear Fellow Microscopists: We are considering of installing an Automatic Liquid Nitrogen Filling System for our SEM. The only source we came across is VBS Industries, Inc. I wonder if any of you would like to share with me your experience with any automatic LN2 filling system. Are they dependable? Are there other sources that sell similar type system? Any feed back will be greatly appreciated.
Pearl W. Yip Rome Lab yip-at-maxwell.rl.plh.af.mil
There was a long thread on this subject in the early days of the listserver. Perhaps it resides in Nestor's or the Florida archives??
I put in my comment that I would never have auto LN fillers again. We had them on TEMs and SEMs in the 70s and early 80s and they all failed catastrophically. (I guess there is no simple, benign failure mode when the possibility of emptying a large LN cow over an instrument and into an unoccupied room exists)!
Long term reliability under extreme temperature excursions seemed to be the problem.
However, to be fair, we are talking 20+ year old technology. This is the wonderful 90s...
One way to examine your marine eggs would be to use the high-pressure freezer to freeze a suspension of washed eggs in distilled water (a roughly 200 micrometer thick plug, 1000 or more micrometers in diameter). Then fracture, etch, and coat as for a TEM replica but use the cryoSEM to look at the rough surface of the fracture. By regulating the amount of etch you could see the surface of the egg as well as cross-sections of the layers of the walls. Paul Walther's articles on double layer coating may be helpful.
Jacob
Jacob Bastacky, M.D. Room 116 Donner Laboratory Lawrence Berkeley Laboratory EMail: sjbastacky-at-lbl.gov University of California Phone: (510) 486-4606 Berkeley, California 94720 Fax: (510) 486-4750
Dear Larry: We've had consistent success removing cover slips from Epon capsule-embedded monolayers with a combination of the methods mentioned by Gib and Greg. We dip the epon block with attached glass or plastic fragments into liquid nitrogen (block can already be attached to chuck). Then using a razor blade gently pry up the rapidly-warming fragment. Sometimes it takes a couple of cooling/warming cycles to obtain sufficient area. Don Gantz Boston Univ Med School gantz-at-med-biophd.bu.edu
Please post the attached ad for a Research Electron Microscopist as soon as possible. If you have any questions, please call me at (217) 244-2944, fax (217) 244-2946.
University of Illinois at Urbana-Champaign Materials Research Laboratory
RESEARCH ELECTRON MICROSCOPIST
The Materials Research Laboratory at the University of Illinois is seeking an experienced electron microscopist as a staff member in the Center for Microanalysis of Materials. The Center is a major research facility with eight electron microscopes as well as instruments in surface microanalysis, x-ray diffraction and other analytical techniques.
The person will work mainly on STEM and TEM but should have experience and the flexibility to work on other techniques if needed. The Center has six TEMs. We are particularly interested in hiring a person with experience in working with field emission TEMs. The Center currently has a VG HB 501 and is expected to purchase a new FEG-TEM soon. The person appointed will have primary responsibility for these instruments. Experience in EDX or EELS is also important. The main responsibility of the position would be to facilitate the research of approximately 100 users yearly on TEM and STEM. There will also be ample opportunity to carry out interactive research in the facility with the wide range of research programs.
This position requires a Ph.D. with at least three years experience with electron microscopes. Salary is commensurate with experience and qualifications.
This is a regular full-time appointment with standard university benefits. The person appointed should be able to begin work between June and August, 1997. In order to ensure full consideration, applications must be received by March 15, 1997. Please send letter of application, resume, and names and addresses of three references to J. A. Eades, c/o Donna Jacobs, University of Illinois, Materials Research Laboratory, 104 South Goodwin Avenue, Urbana, Illinois 61801, phone (217) 244-2944. For technical information, call J. A. Eades at (217) 333-8396.
The University of Illinois is an Affirmative Action/Equal Opportunity Employer.
Donna Jacobs MRL Administration University of Illinois 104 South Goodwin Avenue Urbana, Illinois 61801 Phone (217) 244-2944 Fax (217) 244-2946 email - jacobs-at-uimrl7.mrl.uiuc.edu
} } Date: Tue, 7 Jan 1997 00:41:06 -0500 } } From: PHOBOS11-at-aol.com } } Subject: Wanted Balzers Electronics } } To: Microscopy-at-Sparc5.Microscopy.Com } } Status: RO } } } } ------------------------------------------------------------------------ } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Hi Al,
We do have a new Balzers EVM-052 E-beam gun power supply. Would you please give us an offer.
Have a nice day.
Ya Chen
Ya Chen
*** My email address has been changed to: ychen14-at-facstaff.wisc.edu *** ========================================================================== Cryo/SEM Coordinator Integrated Microscopy Resource (IMR)-- III M M RRRRRR an NIH Biomedical Research Resource I M M M M R R University of Wisconsin, Madison, WI I M M M RRRRRR 1675 Observatory Drive #159 I M M R R Madison, WI 53706, USA I M M R R TEL : 608-263-8481 I M M R R FAX : 608-265-4076 III M M R R Email:ychen14-at-facstaff.wisc.edu ========================================================================== IMR WWW Home Page: http://www.bocklabs.wisc.edu/imr.html
} Dear All } I would appreciate suggestions for examining 80 micron eggs in seawater or distilled water by SEM where the user wants to compare fresh egg surfaces (therefore cryo?) with conventionally fixed, dehydrated and critically point dried eggs. } .....
} I have also frozen them just mounted in a water film, but } some have simply sheared off the standard smooth stub - } should I try poly-L-lysine or super glue? } ........
} A separate problem seems to be that while the crustacean } in question is marine/estuarine and the eggs stand fresh } water for a while (therefore for rinsing), even after 3 or 4 } distilled water changes I still see a fine, dried layer of } salt over everything. The rinsing is done in a watchglass } and the water was almost completely removed with an } autopipette before refilling. } } } Thanks in advance - Keith Ryan } } ++++++++++++++++++++++++++++++++++++++++++++++++++ } Plymouth Marine Laboratory, Citadel Hill, } Plymouth, Devon PL1 2PB, England } } e-mail: k.ryan-at-pml.ac.uk } PML web site: http://www.npm.ac.uk/pml } ++++++++++++++++++++++++++++++++++++++++++++++++++
Keith,
Here is my 2 cents.
1. Coating of poly-L-lysine do help the sample adhere to substrate.
2. Did you have tried freeze-substitution followed by either fast-freezing again, freeze-drying, cryo-coating, and cryo-SEM observation, or dehydration, critical point drying, and SEM observation at RT?
3. I agree with George Braybrook's comment that there is a mucous layer on the egg surface.
With best wishes!
Ya Chen
Ya Chen
*** My email address has been changed to: ychen14-at-facstaff.wisc.edu *** ========================================================================= \ / Integrated Microscopy Resource (IMR)-- \ / __ an NIH Biomedical Research Resource TEL : 608-263-8481 \/ / / University of Wisconsin-Madison FAX : 608-265-4076 / / / 1675 Observatory Drive #159 Email1:ychen14-at-facstaff.wisc.edu / /__/_ Madison, WI 53706 Email2:chen-at-calshp.cals.wisc.edu ========================================================================= IMR WWW Home Page: http://www.bocklabs.wisc.edu/imr.html
It occurred to me that to be sure that your treatments did not introduce any artefacts on the egg surface you might try a Wild (Leica) Elsam accoustic microscope. I'm not very familiar with them but there is the potential (at least) to look at them in seawater or other isotonic solution.
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Dear All
I would appreciate suggestions for examining 80 micron eggs in seawater or distilled water by SEM where the user wants to compare fresh egg surfaces (therefore cryo?) with conventionally fixed, dehydrated and critically point dried eggs.
I was interested to see your reference to removing mucus with EDTA. Would you be so kind to offer a little more info on this. We are starting to do more work on cilial tracts on the head tentacles of micromolluscs for one of our malacologists and often have problems with mucus.
Cheers,
Geoff Avern Microscopy Laboratories Australian Museum Sydney, Australia
As for the salt on the surface after 3 or 4 washes, not much help I'm afraid, just a thought. Is there a mucosal surface layer that the distilled water is drawing the salt out of ?? If so, they might need an EDTA treatment first to remove mucus. Then again, this mucus might be the surface you need to see??? This might be a case of "a rock and a hard place", but sucessful cryo should tell you what is on the surface if you can get a fracture through an egg.
Hope this is helpful.
Cheers :) George Department of Earth and Atmospheric Sciences University of Alberta Edmonton, Alberta T6G 2E3 Canada ph: 403-492-5746 fax: 403-492-2030
} We are considering of installing an Automatic Liquid Nitrogen } Filling System for our SEM. The only source we came across is VBS } Industries, Inc. I wonder if any of you would like to share with me your } experience with any automatic LN2 filling system. Are they dependable? Are } there other sources that sell similar type system? Any feed back will be } greatly appreciated. } Dear Pearl, Our automatic LN2 controllers are from Torr Vacuum, Inc. We have had several disasters: 1) The LN2 source--a very large tank about 200 m from our lab--would occasionally run dry; then the solenoid would over- heat. Usually it would open, but occasionally it would fuse and draw current until someone noticed (see #3). 2) The filler shut-off failed on the system attached to our EDS detector. LN2 poured into and over the dewar until the outer bottle deformed and ice formed all over the in- side and outside of the system. We had to warm up everything, dry every- thing out and re-form the outer bottle--it had a concave bottom originally, but was convex after the disaster. Luckily, everything worked out well, and the detector is still functioning a decade later with its specified resolution. 3) For some reason--not an empty LN2 tank--the solenoid on the line on the 200 kV TEM fused and heated the plastic foam insulation starting a fire. The fire was, fortunately self-limiting; the event occurred after hours on a Friday before a holiday weekend and was not discovered until the next Tuesday. We have not lost any expensive equipment, but there was certainly the potential for such losses. I don't think our problems were the fault of Torr Vacuum; they seem to be inherent in automatic LN2 systems. If you can avoid such systems, I would reccommend you do so. Good luck--especi- ally if you must use them. Yours, Bill Tivol
} Is there a best way to clean the specimen holder on the TEM? How do most people } clean their holders? } Dear Linda, We put our stage tips in a plasma cleaner for ~20 min. That seems to get the petrified grease off, and the method can be used on all tips, not just those constructed of a single piece of metal. It works on our tilt-rotation tip (mostly aluminum), our double-tilt tip (mostly stainless steel) and our aperture holders (phosphor bronze). Yours, Bill Tivol
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } TEM specimen holder cleaning 1/9/97 12:24 PM } } Is there a best way to clean the specimen holder on the TEM? How do most people } clean their holders? } } I normally use Q tip with a little bit of Wenol to clean the holder first. Then use Kimwipes to rub over entire surfce. Sonicate the holder in the acetone bath for 10 min and once again in the fresh acetone bath for another 10 min. After that use air gun to dry it. That is all I do.
*********************************************** * Ming H. Chen, PhD * * Medicine/Dentistry Electron Microscopy Unit * * University Of Alberta. * * Edmonton, Alberta, Canada * ***********************************************
My recommendation would be to use a mixture of Tissue-Tek and carbon dust (from carbon rod sharpener) paste on your cryo-stub. In this mixture the eggs will not sink fast, therefore will have time to carry out the freezing process. I have great LTSEM results using this mixture with unfixed single cell culture and bacteria.
The separate problem about the fine layer of salt, (if the osmatic change is all right!) use larger amount of distilled water to rinse for longer time.
Good luck,
Laszlo J. Veto Electron Microscopy and Image Analysis Pacific Agri-Food Research Centre AAFC vetol-at-em.agr.ca
My recommendation would be to use a mixture of Tissue-Tek and carbon dust (from carbon rod sharpener) paste on your cryo-stub. In this mixture the eggs will not sink fast, therefore will have time to carry out the freezing process. I have great LTSEM results using this mixture with unfixed single cell culture and bacteria.
The separate problem about the fine layer of salt, (if the osmatic change is all right!) use larger amount of distilled water to rinse for longer time.
Good luck,
Laszlo J. Veto Electron Microscopy and Image Analysis Pacific Agri-Food Research Centre AAFC vetol-at-em.agr.ca
On Thu, 9 Jan 1997, Pearl Yip wrote: } Filling System for our SEM. The only source we came across is VBS } Industries, Inc. I wonder if any of you would like to share with me your } experience with any automatic LN2 filling system. Are they dependable? Are } there other sources that sell similar type system? Any feed back will be } greatly appreciated.
I agree with Ron and Bill, they are not dependable. Anything that has moving parts or electronics is not dependable. If you must keep something cold all the time (much better than temp cycling, IMHO), I recommend that you design and build a large LN dewar that keeps the thing cold that you periodically refill every few days or so - much like a dewar for an EDS detector. There are companies out there that will work with you on this if you don't have the facilities to build your own.
Excellent cryo-fracture images of single cells can also be produced, using the Tissue-Tek/Carbon mixture. (My earlier note) It is also a good adhesive, especially on the rough cryo-stub surface. George had very good ideas on cryo-stub surface preparation. This mixture also fractures well, exposing ALL inner surface of the fractured eggs "embedded" in it. I hope it will work well for you.
Regard,
Laszlo
Laszlo J. Veto Electron Microscopy & Image Analysis Pacific Agri-Food Research Centre, AAFC Ph: 250-494-7711 e-Mail: vetol-at-em.agr.ca
Linda Iadarola requested information on cleaning TEM specimen holders. A commonly used technique is to polish with a metal polish such as Wenol or Pol then either wipe or rinse in methanol. Extreme care does need to be taken to avoid trapping the polishing paste in the crevices of the holder. Also, depending on the type of specimen holder, ultrasonic cleaning must NOT be used since the potential exists to weaken or break epoxy bonds (particularly in the case of cyro holders).
Another possibility is to plasma clean the holder. Most of the contamination resident on holders is organic (hydrocarbon). An air or oxygen/argon plasma is quite effective in reducing this contamination. The plasma creates disassociated oxygen which chemically combines with the carbonaceous material and reduces it to CO, CO2 and H2O. Depending on the ion energies used, cleaning can occur without adversely effecting the specimen holder.
Should you have any further questions, please do not hesitate to e-mail me directly.
Best regards,
Paul E. Fischione
E.A. Fischione Instruments, Inc is the manufacturer of the Model 1400 Plasma Cleaner.
G'day everybody and Happy New year! Would any of you kind electron microscopists have looked at the growth rings in seal teeth or any mammalian teeth, please? And how did you do that? And is there a relationship between the ratio of cementum and dentine to the age of the mammal? Thank you kindly Cheers Gerry nash
Ms Geraldine Nash Electron Microscopist
EM Unit Australian Antarctic Division Channel Highway Kingston Tasmania 7050 Australia Ph: + 61 03 62 323 322 Fax: + 61 03 62 323 351
} I'm in a twisty little maze of references, all different. } } Can anyone tell me the full name of Phil. Mag.? } } Thanks in advance, } } Rick Mott
Philosophical Magazine? Your nearest university library should have a reference work that lists periodical names and official abbreviations. "Should" because there *is* such a thing, and they ought to have it. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Microscopy Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
I would appreciate suggestions for examining 80 micron eggs in seawater or distilled water by SEM where the user wants to compare fresh egg surfaces (therefore cryo?) with conventionally fixed, dehydrated and critically point dried eggs. . . . . ************************************* You have two major problems: Sticking and retaining the processed eggs onto a substrate prior to coating and earlier, removing all traces of salt from the eggs . You could try poly-l-lysine. The old technique, which works well for specimens of that size range, is a drop of a sticky solution onto a substrate. After solvent evaporation a very thin "permanently" sticky layer remains. The solution is prepared by dissolving the gum of clear sticky tape in chloroform overnight. Push a couple of meters of tape into a small jar and add about 50 ml of chloroform. If you require a very clean background the solution can be millipore filtered. If some low power images are needed, than freshly cleaved mica gives a very clean background. At zero tilt, the mica is very dark in secondary mode.
Removing salt from marine specimens can be very difficult. Leaving the specimen for a lengthy period in water, even after fixation, may damage structures. An appropriate concentration of ammonium acetate provides the right molarity and the aqueous (or ethanol) solution leaves no residue. Others have referred to mucous which may or may not be removed. EDTA fell out of favour as a decalcifier some time ago. For the same reasons I would prefer a broad spectrum enzyme. I used a snail enzyme many years ago for removing mucous, but your local biochemist should be able to advise. Hope this is some help with this difficult problem. Happy New Year Jim Darley Probing & Structure (Microscopy Supplies & Accessories) PO Box 111, Thuringowa QLD 4817 Australia
Phone +61 77 740 370 Fax: +61 77 892 313 A great microscopy site: http://www.ultra.net.au/~pns/
Please, can you tell me how i can participate to this helpfull Newsgroup ? Thanks Christian (student preparing a Microscopist PhD in Nantes University ) .
} Dear Fellow Microscopists: } We are considering of installing an Automatic Liquid Nitrogen } Filling System for our SEM. The only source we came across is VBS } Industries, Inc. I wonder if any of you would like to share with me your } experience with any automatic LN2 filling system. Are they dependable? Are } there other sources that sell similar type system? Any feed back will be } greatly appreciated. } } Pearl W. Yip } Rome Lab } yip-at-maxwell.rl.plh.af.mil
Pearl,
As others have said, these systems do seem to unreliable and considering the value of the equipment they are attached to, I would not trust them. I would even be wary about LN2 level alarms - they seem to be reliable, but do you really want to have the safety of perhaps 500k dollars or more of equipment depending on one?
Anyway, what is the problem with a regular manual schedule of re-filling?
You don't actually say what you are filling with LN2.
If it is an EDX detector, I would suggest that if you are really concerned, you should have a routine for users to disconnect the HT from the detector. Then if the detector should run dry, there is no risk of damage (although, to be honest, I have, more than once, had an EDX detector go dry while the HT was on and survive apparently unharmed, but I don't recommend anyone trying it). However, this might require that you allow the detector to restabilise following reconnection of the HT.
If you are filling LN2 traps on the vacuum system, then I would caution you about running them continuosly anyway - over a period of time this will actually degrade your vacuum. All cold traps should be allowed to warm to room temperature at least once a week and the vacuum stabilise. If not, you will gradually get a build up of ice and other contaminants on the traps which, eventually will outgas at a sufficient rate to contaminate your system.
} } TEM specimen holder cleaning 1/9/97 12:24 PM } } Is there a best way to clean the specimen holder on the TEM? How do most } people } clean their holders?
Don't :)
No part of a specimen holder that goes into the vacuum of a TEM needs to be, or should be touched by dirty fingers (or anything else). If you follow appropriate handling procedures, in the majority of cases, holders do not need cleaning.
They may often 'look dirty' but this is usually some sort of oxidation and doesn't cause any problems in the TEM. Unless a particular specimen rod is, without question, causing contamination problems when you do microanalysis or microdiffraction, and the problems really are only apparent with that specific rod, then 'if it ain't broke, don't fix it'.
Certainly, there should be no necessity for a regular cleaning routine and in general, I have never cleaned holders for which I have had responsibility. The only exceptions are the external O-ring seal on the barrel and the jewel bearing on the tip.
Having said that, problems do occur. Simple holders (single tilt) can usually be cleaned successfully by ultrasonic in a solvent, rinse in distilled water and warm air blow dry. However, more complex holders may be almost impossible to clean fully - it is difficult to fully penetrate all the crevices and internal spaces effectively and solvent/ultrasonic may weaken or damage expoxy joints and seals. Plasma discharge is pretty effective, but again is unlikely to fully penetrate internal spaces - although if you have serious contamination in an internal space then whoever is responsible probably needs introducing to a few of life's realities - try to find an old HT tank for them to clean!
Whatever the problem, don't use wehnol or similar abrasive metal polishes - if it needs something that powerful to remove the dirt, then it wasn't a problem to start with - but it may be after you have filled the crevices with metal polish.
Minor contamination of holder tips by specimens can sometimes be a problem. Usually, this can be cured by leaving the holder, without a specimen, in the TEM contiuosly for a long period - say a weekend - and it will pump clean.
The only exception to all the above is cryo-holders. They frequently get horribly dirty. Often, however, it is only the tip region that is the problem. If you don't have access to a suitable plasma system, then just the tip can be suspended and ultrasoniced in a solvent - also, check with the manufacturer regarding cleaning. You may find that you have to start by removing the worst with wooden cocktail sticks. You will avoid the worst problems if you can get users to remove specimens from the holders while still frozen.
Regards, Larry Stoter
--------------------------------------------------------------- Dr L. P. Stoter Technical Editor, MICROSCOPY & ANALYSIS Technesis 17, Rocks Park Road email: LPS-at-teknesis.demon.co.uk Uckfield, E. Sussex Phone: +44 (0)1825 766911 TN22 2AT Fax: +44 (0)1825 766911 United Kingdom ---------------------------------------------------------------
} } I'm in a twisty little maze of references, all different. } } } } Can anyone tell me the full name of Phil. Mag.? } } } } Thanks in advance, } } } } Rick Mott } } Philosophical Magazine? } Your nearest university library should have a reference work that } lists periodical names and official abbreviations. "Should" because there } *is* such a thing, and they ought to have it. } Phil } } &&& Illigitimi non carborundum &&&&&&&& } Philip Oshel } Microscopy } Station A } PO Box 5037 } Champaign, IL 61825-5037 } (217)244-3145 days } (217)355-3145 evenings } oshel-at-ux1.cso.uiuc.edu } *** looking for a job again ******************
But beware that there are Phil. Mag. A and Phil. Mag. B. I don't know when each issue was split into two, but is was some time ago.
A postdoctoral position is available immediately in the department of cell biology at the University of Pittsburgh. This position within the Muscular Dystrophy Research Center and Imaging Center will be focussed toward using microscopy to study the dystrophin cytoskeleton in skeletal muscle, the ultimate goal being to optimize therapeutics (gene delivery) currently under development within the center. Initially the project will use live cell, confocal, and EM methods to study the expression, and deposition of components of the dystrophin cytoskeleton (dystrophin, sarcoglycans, dystroglyans and the ECM) and their role in the development and maintenance of muscle fiber structure. This position is funded for 3 years
This position requires a Ph.D.and experience in microscopy (the specific field is unimportant) This is a regular full-time appointment with standard university benefits
The University of Pittsburgh is an equal opportunity employer
Please respond by e-mail to swatkins-at-pitt.edu
-- ------------------------------------------------- Simon C. Watkins Ph.D Associate Professor Director SBIC University of Pittsburgh Pittsburgh PA 15261 tel 412-648-3051 fax 412-648-2004 -----------------------------------------------
-- Leon A. Metlay, M.D.,Associate Professor of Pathology and Laboratory Medicine University of Rochester Medical Center Phone: (716) 275-5691 P.O. Box 626 Fax: (716) 273-1027 Rochester, NY 14642 lmetlay-at-acu.pathology.rochester.edu http://www.urmc.rochester.edu/smd/pathres/URPLM.html "Most ass drivers are evil, most camel drivers are decent, most sailors are saintly, the best among physicians is going to Gehenna, and the best of butchers is a partner of Amalek" -R. Judah, in Mish. Kidd. 4:14
The filler for an LN trap over the DP on our JEOL 2000FX TEM malfunctioned, and a tank of LN2 emptied out all over the diffusion pump. The microscope shut down, luckily valving the column off from the DP. The water lines froze, including the water in the baffle at the top of the pump. This caused the baffle to crack, and when it warmed up again, the pump and reservoir tank flooded with water. The next morning the microscope was found in the OFF condition, and, no problem being evident, was simply restarted. This caused an emulsion of DP oil and water to be sucked into the rough pump, which *was* evident, and the machine was immediately turned off. The damage was done however, and a complete teardown and cleaning was necessary, taking a couple of weeks.
So if you use a filler system, be sure to provide a way to funnel LN away from the microscope, in the event that the solenoid fails to close properly and the tank empties.
Microscopists, at least in the U.S., may want to learn a new acronym. On 7 January I attended a forum at the National Institute for Standards and Technology which started the process to form NACLA, the NAtional Council for Laboratory Accreditation. While it is in its early infancy, this group is seen as a way to resolve the current crisis in laboratory accreditation, which affects more of the members of the microscopy listserver than one might imagine.
Those of you in academic institutions can now lean back, relax and have a good laugh at the expense of the rest of us. The academic world learned long ago that accreditation was a good idea, but it was only going to work if the standards were set high enough and the process was rigorous enough that the results were acceptable to everybody involved. The result is mutual recognition of accreditations done by various bodies, some based on regional associations and others by national groups which derive from various professions. The result is a system that works pretty well.
For three different groups of laboratories, however, accreditations are not mutually recognized, for a variety of reasons. Much of the time of the forum was devoted to describing the problems of testing, analytical and calibration laboratories (medical and environmental laboratories have whole additional layers of problems) operating within manufacturing organizations and doing product-related analytical work, operating as independent laboratories or operating within the Federal government. The crisis is that laboratory folks are spending so much time dealing with duplicate accreditation visits that there is little time left to get any work done. Approximately 150 different organzations in the U.S. accredit laboratories. The current record is a laboratory that holds 102 separate accreditations from various levels and agencies of government, different industrial users of laboratory data and several accreditation associations. Each of these accreditations requires that an audit be conducted, ranging from submission of duplicate documents to be analyzed in the same way to on-site visits taking several days.
Underlying this mess are several types of problems, including the fact that different agencies accredit to different standards, the conflicting requirements of different laws and regulations, the lack of trust among accreditors and the vital nature of laboratory data for issues affecting health and safety. What I learned at the forum is that the problems of duplicate accreditations and redundant requirements that I see in an independent analytical laboratory are similar to problems experienced by laboratories in government, even within the same agency.
Is this an issue for microscopists? I think it is. Some of us are already well familiar with accreditation programs affecting anyone who does analysis by light or electron microscopy for asbestos. Others are trying to figure out how to deal with ISO 9000, which is intended for organizations that produce goods and services, but not really focused on laboratory operations. The organizers of NACLA are working to develop a system which will have all laboratory accreditations traceable to a single, international standard, probably similar to the present ISO Guide 25. They are also trying to resolve the present conflicting roles of NIST in laboratory accreditation, where NIST is at the same time accrediting accreditors, operating an accreditation system and operating calibration laboratories which should be accredited. At the same time, they are working to make all accreditations traceable to the Federal government through NIST in order to make them acceptable internationally. Finally, they are working to create a system in which various accreditation agencies recognize each other, probably because the accreditors themselves have been accredited by a process of peer review.
NACLA is just beginning, but microscopists should be aware that it is coming and, along with it, an increasing probability that each of our laboratories will be going through some sort of a standardized accreditation process.
I'm not aware that the proposal to develop NACLA is available on the web, but it should be available from NIST. If there are any questions, I'd be happy to try to answer them.
Andy
Andrew W. Blackwood, Ph.D. Structure Probe, Inc. P.O. Box 656 West Chester, PA 19381-0656 Ph: 1 610 436 5400 FAX: 1 610 436 5755 e-mail: ablackwood-at-2spi.com WWW: http://www.2spi.com
Paul wrote: } Another possibility is to plasma clean the holder. Most of the } contamination resident on holders is organic (hydrocarbon). An air or } oxygen/argon plasma is quite effective in reducing this contamination. The } plasma creates disassociated oxygen which chemically combines with the } carbonaceous material and reduces it to CO, CO2 and H2O. Depending on the } ion energies used, cleaning can occur without adversely effecting the } specimen holder.
Can Be cups be cleaned in plasma systems without damage?
Larry wrote:
} Certainly, there should be no necessity for a regular cleaning routine and } in general, I have never cleaned holders for which I have had } responsibility. The only exceptions are the external O-ring seal on the } barrel and the jewel bearing on the tip.
Does your experience include AEM in high resolution FEG's? We are about to purchase a 300 keV FEG and would like to know how critical specimen and rod cleanliness is.
Ciao for now, Ken
Kenneth JT Livi Department of Earth and Planetary Sciences 34th and Charles Streets The Johns Hopkins University Baltimore, Maryland 21218
Jim Darley is right about the EDTA, we tried it many moons ago (memory is the first thing to go!!) but found 1500 NF units/ml ovine hyaluronidase in millipore filtered seawater was better, for spermatoza at least. (D. G. Atwood et al,1975, Journal of Microscopy, vol 103, pp. 259 to 264.) I'll send you a reprint if you like!
"Others have referred to mucous which may or may not be removed. EDTA fell out of favour as a decalcifier some time ago. For the same reasons I would prefer a broad spectrum enzyme. I used a snail enzyme many years ago for removing mucous, but your local biochemist should be able to advise."
Cheers :) George Department of Earth and Atmospheric Sciences University of Alberta Edmonton, Alberta T6G 2E3 Canada ph: 403-492-5746 fax: 403-492-2030
An issue which I have not seen mentioned in the responses to this thread is the video bandwidth of the SEM amplifiers. SEM's are not (in general) designed to obtain quality images at TV rates, and the amplifiers are not usually capable of passing information at a high enough rate. This is quite separate from the noise issue, and no amount of frame averaging can correct the problem.
A way you can see this is to turn the electron beam off, turn up the PMT voltage until you can see noise pulses, then grab a single frame at TV rate. If you look closely, you will see that the noise pulses are not spots, but short lines. As an approximation, you can never get finer horizontal detail in your image than the length of these lines.
The demonstrations you will see by board vendors showing how their boards clean up a noisy image are just fine, but remember that they are using high quality CCD video cameras as the image source, and high bandwidth amplifiers, with the noise artificially enhanced, for their demonstrations.
As people have commented, one can get a useful image by frame-averaging a TV rate signal, but (in most cases, at least) don't expect it to have the same quality as a slow-scan image.
Tony Garratt-Reed.
**************************************************** **************************************************** ** ** ** Anthony J. Garratt-Reed ** ** Room 13-1027 ** ** Center for Materials Science and Engineering ** ** Massachusetts Institute of Technology ** ** 77 Massachusetts Avenue ** ** Cambridge, Massachsetts 02139-4307 ** ** U. S. A. ** ** ** ** Phone: 617-253-4622 ** ** Fax: 617-258-5286 or 617-258-6478 ** ** ** **************************************************** ****************************************************
**************************************************** **************************************************** ** ** ** Anthony J. Garratt-Reed ** ** Room 13-1027 ** ** Center for Materials Science and Engineering ** ** Massachusetts Institute of Technology ** ** 77 Massachusetts Avenue ** ** Cambridge, Massachsetts 02139-4307 ** ** U. S. A. ** ** ** ** Phone: 617-253-4622 ** ** Fax: 617-258-5286 or 617-258-6478 ** ** ** **************************************************** ****************************************************
} Can Be cups be cleaned in plasma systems without damage? } Dear Ken, Yes. I'd be careful where the pump exhaust is vented, however. The presence of Be dust in the exhaust is a possibility (at least in theory), and that is *very* toxic. The particles would likely be in the submicron range, and therefore easily inhaled. I'd think it unlikely that a Be cup with a smooth surface would be etched too readily. Does anyone else on the list have other info? } } Does your experience include AEM in high resolution FEG's? We are about to } purchase a 300 keV FEG and would like to know how critical specimen and rod } cleanliness is. } No, I have no experience with FEG instruments. I'd think the limiting factor would be how a dirty rod affects the vacuum. If you are interested in looking at specimens which have clean surfaces, the contamination would also be a major concern. Yours, Bill Tivol
A nice resource for checking full journal titles from standard abbreviations can be found at Chemical Abstracts WEbsite: ...its also nice cause they have the CODENs in the list and with Netscape or Internet explorer, one can type "command-f" to find the abbreviation of interest. This has all CAS-journals, which is most of the good ones... its at:
http://info.cas.org/sent.html
I recommend bookmarking it..
as Martha might say "it's a good thing."
Brendan Foran
_____________________________________________________________________ Brendan J. Foran Ph.D. ...currently just a "Post-Doc"
Dept. of Materials Science & Engineering 2125 H.H. Dow building The University of Michigan phone:(313)-763-4196 2300 Hayward Street fax: (313)-763-4788 Ann Arbor, MI 48109-2136 bforan-at-umich.edu _____________________________________________________________________
--IMA.Boundary.561329258 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Description: cc:Mail note part
Bill Mason responded to an inquiry regarding Kodak digital cameras:
We have used a number of digital cameras, including Kodak. The Kodak cameras are not really so suitable for image analysis of the type you mention because they are really on 8 bit cameras as standard (256 grey levels), so have limited dynamic range.
I though that the following from Kodak's Readme file that comes with the latest driver download might be helpful especially since it seems to say that the data for their DCS 420/460 cameras are12 bit images:
"When the "12 bit Acquire" checkbox on the driver is checked, the driver will acquire the image data into Photoshop Version 2.5 or higher with 12-bit resolution per color. The file size is doubled and the acquire time is slightly longer. If the "12 bit Acquire" checkbox is unchecked, the acquire module passes 8-bit image data back to Photoshop.
Kodak's DCS cameras capture image data with a 12-bit analog to digital converter. Photoshop supports a 16-bit per pixel mode, however Kodak calls the new driver feature "12 bit acquire" so that we will never mislead customers into thinking that we use a 16-bit analog to digital converter.
Our DCS drivers that run on Macs and PCs maintain this 12-bit resolution through the image processing path. Early versions of Photoshop required acquire modules to reduce the image data resolution to 8-bits per pixel per color just before passing the image data back to Photoshop. Photoshop Version 2.5 or above allows acquire modules to provide the image data with either 8 or 16-bits per pixel per color. Adobe calls these 24-bit and 48-bit RGB Color modes." Any and all copyright notices may apply to the preceeding excerpt.
I have no financial interest in nor am I recommending use of Kodak,Photoshop,Mac etc.
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Dear MSA listserver subscribers, I am a graduate student (master's) trained in EM. I was wondering if anyone could tell me what range of starting yearly salary I should expect.
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Dear Colleagues:
I have read, with interest, all of the discussions concerning cleaning of TEM specimen holders. As has been mentioned, plasma cleaning has been determined to be a highly effective means to remove organic contaminants from both a specimen and a specimen holder. Significant work has been done in quanitfying the effects of Plasma Cleaning since Dr. Nestor Zaluzec at Argonne National Lab received his patent on the technique.
I am quite sure that there will be some lively discussions at the MRS Meeting in San Francisco during the TEM Specimen Preparation Symposium. If you'd like to get a jump start on the discussion, I can refer you to two articles on Plasma Cleaning that may be of interest:
1) "Simultaneous Specimen & Stage Cleaning for Analytical Electron Microscopy", Microscopy Today October 1996. Volume 96-8, Page 16, by yours truly. This is a very general discussion of the process.
2) "Reactive Gas Plasma Specimen Processing for Use in Microanalysis & Imaging in Analytical Electron Microscopy" by Nestor Zaluzec. This is a preprint of a paper to be presented at MSA in Cleveland this coming August. This paper provides parameters for processing and gives quantified data concerning the effects of plasma cleaning.
I can provide you with copies of both papers if you have an interest. You may also be interested in reading Dr. Zaluzec's patent (#5,510,624). I can also send you a copy of that if it is of interest.
If you have an interest in subscribing (IT'S FREE!) to Microscopy Today, you should send an e-mail request to Don Grimes at MicroToday-at-aol.com. It is a fine publication and I highly recommend it to all microscopists. I have no financial interest in Microscopy Today - I'm just a faithful reader!
DISCLOSURE I must also point out that South Bay Technology does license this tachnology from Argonne National Lab pursuant to the above mentioned patent. We also produce a plasma cleaner which is designed to clean specimens and holders so we have a vested interest in making you aware of the technique.
Please address your requests to my attention.
Best regards-
David Henriks TEL: 800-728-2233 (toll-free in USA) South Bay Technology, Inc. 714-492-2600 1120 Via Callejon FAX: 714-492-1499 San Clemente, CA 92673 USA e-mail: henriks-at-southbaytech.com http://www.southbaytech.com
Manufacturers of Precision Sample Preparation Equipment and Supplies for Metallography, Crystallography and Electron Microscopy.
} Larry wrote: } } } Certainly, there should be no necessity for a regular cleaning routine and } } in general, I have never cleaned holders for which I have had } } responsibility. The only exceptions are the external O-ring seal on the } } barrel and the jewel bearing on the tip. } } Does your experience include AEM in high resolution FEG's? We are about to } purchase a 300 keV FEG and would like to know how critical specimen and rod } cleanliness is. } } Ciao for now, } Ken } } Kenneth JT Livi } Department of Earth and Planetary Sciences } 34th and Charles Streets } The Johns Hopkins University } Baltimore, Maryland 21218 } } klivi-at-jhu.edu (e-mail)
Kenneth,
I have done a lot of AEM, up to 300kV although not on FEGs. However, much of this has included EELS which will pick up C contamination more easily than any other method. Specimen rod cleanliness is important but I guess the point I was trying to make is that you shouldn't get it dirty in the first place! In general, and with proper care I believe that cleaning the specimen rod is unnecessary.
I assume you are not talking about UHV at the specimen - if you are, then the whole question of cleanliness is a different order of magnitude. If you are talking about UHV at the specimen, then probably Nestor is the person to comment on this.
Specimen cleanliness is a somewhat different issue and there are certainly some specimen prep procedures, and types of specimen that can lead to contamination problems. For example, there are some pretty gungey mixes around for electrochemical thinning - I used to put plenty of glycerol into one of my favourite mixes for stainless steel - these need carefully removing from specimens. Also, dirty ion beam thinners make pretty good fine grain carbon coaters. Be careful.
} At 08:48 10.1.1997 +0000, you wrote: } } } If it is an EDX detector, I would suggest that if you are really concerned, } } you should have a routine for users to disconnect the HT from the detector. } } Then if the detector should run dry, there is no risk of damage (although, } } Hello Larry, } } I would not give people the idea that you can let an EDS detector warm up } while connected into the microscope. This is true especially with detectors } with window. The dewar is pumped down to its ultimate vacuum by a chemical } sorption pump. If you let the detector warm up the pressure in the vacuum of } the dewar gets worse than that inside the microscope. The window fitting } does not normally like this direction of pressure difference and the result } may be your window (Be or polymer) blowing out into the microscope. At least } Tracor recommends to remove the detector before warming it up and again } cooling it down before installing to the microscope. } } Regards, } Jouko
I certainly wouldn't suggest anyone try warming up EDX detectors, on or off the microscope, without first talking to the manufacturer regarding warming/cooling procedures. However, from personal experience of Be window detectors, they can survive warming up while on a TEM column, so if it does happen to you (and you are responsible), try cooling it down again, before you cut your throat :)
With UTW detectors, you probably won'tt be so lucky.
Regards, Larry Stoter
--------------------------------------------------------------- Dr L. P. Stoter Technical Editor, MICROSCOPY & ANALYSIS Technesis 17, Rocks Park Road email: LPS-at-teknesis.demon.co.uk Uckfield, E. Sussex Phone: +44 (0)1825 766911 TN22 2AT Fax: +44 (0)1825 766911 United Kingdom ---------------------------------------------------------------
Thanks for all the pointers to Philosophical Magazine. Much appreciated.
Unfortunately, I'd already discovered the highly obscure publication Philosophy of Magic. After the obligatory puff of greasy black smoke, I find myself in the form of a large green frog. You have no idea how complicated it is typing this with webbed fingers...
On the bright side, my debugging skills seem to have improved markedly.
VBS is the only automatic LN2 filling system I have seen commercially, although there may be others. However, you might want to design your own system, using cryogenic solenoid valves and sensors, and providing LN2 from cylinders. It is fairly inexpensive to do this. I can send you information on a system we built and used in our lab for some time, if you are interested. I presented a poster on this system at the 1994 MSA meeting and the description in included in the Proceedings from that meeting. One problem we ran into with our system is that we did not have a failsafe mechanism to shut the system off when the cylinder ran out of liquid. The result was that nitrogen gas would continue to fill the dewar and eventually would blow out the remaining liquid. I think this can be remedied by making some changes to the system. Regards, Melanie A. Behrens Texaco, Inc. P.O. Box 509 Beacon, NY 12508 914-838-7261 behrema -at- Texaco.com or MelanieOwl -at- aol.com
Dear Gerry, I have looked at the growth rings in human (child's) teeth, and the dark marks left by early stress events. I felt that light microscopy gave a better view of the dark marks, but examining the teeth was not difficult. I just gold-coated and examined as usual. I did not try to determine any ratios. I do believe that there is some shrinkage, due to dehydration and cryo would be a more rigorous way to go. Good luck, Mary At 02:42 PM 1/10/97 +1000, you wrote:
} Would any of you kind electron microscopists have looked at the growth } rings in seal teeth or any mammalian teeth, please? And how did you do } that? And is there a relationship between the ratio of cementum and dentine } to the age of the mammal? } Thank you kindly } Cheers } Gerry nash Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
Dear Fellow Microscopists, I'm looking for a full time position in a research or imaging= facility lab. =20 I have a BS in Biology and I'm currently persuing a second BS in biomedical= photography with a concentration on photomicrography, and digital imaging. = I'll be graduating on February. You can view my resume at http://www.isc.= rit.edu/~caa3045
My photography, computer skills, research and laboratory experience is= varied. During the summer of 1992, I conducted research on the effects of= hexadecane on genetic variability of nestmate recognition in honey bees at= the University of Colorado at Boulder. During the summer of 1993, as part= of a research program sponsored by the Medical College of Pennsylvania, I= characterized chloride channels in the human colonic cell line T84 using= the patch-clamp technique.=20
My research technician position from January '94 thru June '95 at the= Medical College of Pennsylvania expanded my range of skills. I conducted= experiments on the structural change of F-actin and ankyrin in the= cytoskeleton of lymphocyte using the confocal microscope and various immuno= cytochemistry techniques. The result of this project has already been= published in the journal of Membrane Biology 147, 283-294. In addition, I= used the patch clamp technique to investigate bile duct cells from Cystic= Fibrosis patients, and characterize fibroblast cells (NIH3T3). =20 Also, my position at the Ocular Cell Transplatation Laboratory at the= University of Medcine and Dentistry of New Jersey involved digitizing and= capturing images of the retina, create plates for publication, and created= and maitained the laboratory's website. I am presently the webmaster for = Spectra Services. =20
In addition to my science background the Biomedical Photographic= Communications Department at RIT has exposed me to many computer skills = and medical photography techniques. I have hands on experience on fundus= photography, stereo photography, and I am familiar with the fluorescein= angiogram techniques. In addition, I am experience with many formats of= films processes, black-and-white, and color printing, photomacrography,= photomicrography, darkfield, brightfield, nomarski, phase-contrast,= polarizing, Rheinber, SEM,fluorescence, and confocal microscopy. =20
Also, I have a great interest and experience in digital photography,= multimedia, and computer in general. I have hand on experience with the= window platforms and Macintosh computer (Macintosh major area of strenght).= I am proficient in many imaging and multimedia production softwares such= as photoshop and Multimedia Director, QuarkXpress, Adobe Illustrator, and = Adobe Premiere. In addition I have work experience with HTML and Lingo= programming. =20
My career objective is to become an expert in a wide variety of imaging= enhancing, analysis softwares and equipments and become very= knowledgeable in the area of microscopy (Confocal, TEM and SEM.) And create= interesting interactive multimedia pieces conveying scientific= informations. If you have access to the internet you can view my resume= and some of my images in my web site at http://www.isc.rit.edu/~caa3045 =20 If you think I may contribute to your department or if you need= further information please send me an e-mail to "caa3045-at-rit.edu" or "alm= onte-at-medcolpa.edu" Thanks,
--Ciprian Have fun and keep the sun on your back and a smile on your face. __________________________________________________________ Ciprian A. Almonte Rochester Institue of Technology Biomedical Photographic Communications Rochester, NY 14623-5603
Visit my web site at http://www.isc.rit.edu/~caa3045/ __________________________________________________________
The UC Berkeley Electron Microscope Lab is looking for and EM Tech. What follows is the job announcement.
Staff Research Associate II (PSS 1) Electron Microscope Laboratory $30,200/ year starting salary Job number: 12-411-30/SL Closing date: 1/31/97
Operate and maintain a TEM, Bal-Tec High Pressure Freezing Machine, and JEOL 9000 Freeze-fracture machine. Train students, staff, and other users in TEM technique, including sample preparation. Operate cryofixation equipment for EM sample preparation. Train users in darkroom technique. Learn and apply new techniques as appropriate.
Qualifications: Experience in electron microscopy, especially TEM sample preparation techniques and cryotechniques. Effective communication skills. Experience with TEMs and related equipment. Experience with specimen preparation techniques for TEM. General Lab skills such as preparing buffer solutions and opreating pH meters. Experience with electronic equipment and its routine maintenance. Darkroom experience. Ability to work independently.
If you are interested please contact the UC Berkeley Employment Office.
UC Berkeley Employment Office Room 7-G (Ground Floor) 2200 University Avenue Berkeley, CA 94720 (510) 642-1011 general line (510) 643-9421 TTY for disabled
I have a specimen preparation problem which some of you on the list may be= able to help me with.
I have been using M-BOND 610 to prepare my TEM cross-sectional samples with= great success, but I am now worried that the elevated temperature curing= (200C for two hours) is annealing the thin films I am examining(I am= looking at copper thin films on a quartz substrate, which I sandwich= between wafers of silicon for the cross sections). Has anyone had any good= experiences using a room temperature adhesive for cross-sections which will= be tripod polished and briefly ion milled?
F. Scott Miller Electron Microscope Lab smiller-at-umr.edu University of Missouri-Rolla =20 223 McNutt Hall voice: 573 341 4727 Rolla, MO 65409 USA fax: 573 341 6934
In my ~20+ years of experience, all specimens contaminate to some degree (some slow, some fast) in the microscope. I've seen this in every instrument (TEM, STEM, SEM) I have used from W, LaB6 to FEG instruments, UHV or not. In modern TEM/STEM instruments the majority of this contamination is specimen and stage borne as the manufacturers have generally improved their vacuum systems over the years so that their contribution is small to neglegible.
In the specimen borne regime, the magnitude of the contamination is a function of the sample (metallic, semiconductor, organic, ....) , it's preparation method (electrochemical, chemical, microtoming, ion milling...), the microscope, the probe and probe current. Plus a number of other less well controlled factors.
Rather than draw this out into a very long dicussion, it suffices to say that when critical small probe work is being done, I plasma process my specimens and stage before microanalysis especially in LaB6 and FEG systems. Or if I determine after an experiment starts that the specimen is begining to contaminate, then I remove the sample and the stage from the microscope and process them off-line and then resume to work. The effectiveness of this processing depends upon the gas, pressure, and power of the plasma but is dramatic in most situations. I have been able to minimize/remove specimen borne contamination to a level where I can operate for ~ 8+ hours without significant contamination. Of course, when it reappears (usually now due to the microscope) the specimen is just "reprocessed" and I can continue working. Unfortunately, once surface hydrocarbons are removed you may find out that your sample exhibits electron sputtering in the microscope :-( . This is an effect which we calculated and showed would happen if the conditions are right back in 87 (Zaluzec & Mansfield in Proc. AEM-87). Adding back a very thin layer of spectroscopically pure carbon sometimes cures this problem, with minimal contamination effects.
I also routine apply this process to stages which have Be cups. If you operate under the correct plasma conditions you will NOT sputter/etch material from or onto the stage. This only occurs when the power level of the plasma is too high and you enter the etching or "ashing" regime.
Generally I would recommend a power level of ~ 5-10 W, pressure ~200 mT, processing time ~ 5 min and a 2 stage cleaning. First using pure Argon, followed by pure Oxygen. I have experimentally found that this always produces the best results. In addition, the temperature rise under these conditions is less than 5 C, so specimen/stage heating is almost never a problem.
As per the rules of the Microscopy Listserver. I should point out that all the commerical suppliers (SPI, SBT, EAF) of TEM specimen/stage plasma cleaning technology are licensees of a US Patent, which was issued to my employer Argonne National Lab and ANL obviously has some financial interest in that patent and this methodology.
SCOTT, TURN THAT OVEN DOWN! (Pardon me, I don't often shout.)
Curing M-Bond 610 at 200C for 2 hours is waaaayyyyyy overkill. The instruction bulletin that comes with M-Bond suggests 125 to 160C for two hours, and remember that's for bonding strain gauges to steam boilers!
We never exceed 70C. If we are gluing a specimen on to a grid by clamping the specimen in self-closing tweezers and then inserting tweezers+grid in an oven we cure for 2 hours. (If the glue is still soft (rare) we'll add another hour). If we are curing the specimen to a grid on a glass slide on a hot plate at 70C we find 10 to 15 minutes to be adequate. Remember to put a pan of water in the oven to keep the humidity up during curing!
For temperature sensitive parts we have experienced no problems curing at 30, 40, etc degrees up to 70C. Room temperature curing M-Bond takes overnight. Paul Albarede, France's premiere tripod polisher, routinely cures M-Bond overnight at room temperature, he tells me--arguing that the differential contraction of the Cu grid and the specimen leads to stress being put on the thin specimen when the Cu grid and specimen cool off after bonding at temperature. You can see this with Si if you cure at too high a temperature: the flat polished specimen ends up with a wavy edge like curly lasagna pasta.
NIST-NIH Desktop Spectrum Analyzer (DTSA) Spring 1997 Workshop
A three-day intensive Workshop on NIST-NIH Desktop Spectrum Analyzer (DTSA) will be held at NIST, Gaithersburg, Maryland, March 26-28, 1997. DTSA is a software platform for electron-excited energy-dispersive and wavelength-dispersive X-ray spectrometry developed by Fiori, Swyt, and Myklebust for Macintosh computers. The Workshop will cover practical aspects in utilizing DTSA, including spectrum processing (background and peak interference removal), quantitative analysis for bulk and layered specimens (matrix corrections, including the comprehensive CIT-ZAF resource), analytical electron microscope quantitation for thin foils (Cliff-Lorimer sensitivity factor method), generation of X-ray spectra from first principles, and development of analytical strategy through "desktop" simulations. Attendance at the DTSA Workshop is free, but is limited to 25 attendees.
For reservations and/or information, contact Dale Newbury at dale.newbury-at-nist.gov or telephone 301-975-3921. fax 301-417-1321
Note: DTSA is a software program sold through NIST's Standard Reference Data Program and we therefore have a very small financial interest in the product.
Eric B. Steel, Leader e-mail: eric.steel-at-nist.gov Microanalysis Research Group Office: 301-975-3902 N.I.S.T. FAX: 301-216-1134 Bldg. 222/Rm A113 Gaithersburg MD 20899
Please post the following advertisement for an academic position at The University of Calgary for a Structural Biologist/Microscopist.
STRUCTURAL BIOLOGIST
The University of Calgary Department of Anatomy invites applications for a fulltime academic position as a structural/cell biologist. This position offers an excellent opportunity for independent and collaborative research with other structural biologists employing technologies such as magnetic resonance spectroscopy and x-ray diffraction in the university-wide structural biology group, and for access to the University s Microscopy and Imaging Facility, comprising state-of-the-art electron and computer-based light microscopies. Duties will also include undergraduate teaching and graduate student supervision.
Qualifications include a PhD or equivalent, at least two years of postdoctoral experience, and a proven record of excellence in a research program which includes the development of advanced imaging techniques. Researchers particularly encouraged to apply are those with interests at the cellular or molecular level in an area complementing activities of a Faculty of Medicine research group such as Cancer Biology, Molecular & Developmental Biology, Joint Injury & Arthritis, etc. More information is available at http:/www.ucalgary.ca/~resoff/index.html.
The successful candidate must compete successfully for salary and establishment grant support from the Alberta Heritage Foundation for Medical Research and/or the Medical Research Council, and will have 75% of time protected for research.
In accordance with Canadian immigration requirements, priority will be given to Canadian citizens and permanent residents of Canada. The University of Calgary is committed to Employment Equity.
Please submit a curriculum vitae and statement of research and goals, and arrange for three letters of reference to be sent directly, by February 15, 1997, to:
Dr. D.P. Bazett-Jones Department of Anatomy The University of Calgary 3330 Hospital Drive N.W. Calgary, Alberta, Canada T2N 4N1
Tony King of VG Microtech in the UK (who produce a cryo-SEM, the Polaron LT7400) had some additional comments which he asked me to pass along:
} } } My recommendation would be to use a mixture of Tissue-Tek and carbon } } } dust (from carbon rod sharpener) paste on your cryo-stub. In this } } } mixture the eggs will not sink fast, therefore will have time to carry out } } } the freezing process.
Tony replies: Try tissue tek smear (with carbon dust on a Dry colloidal graphite base; this absorbs the tissue tek bulk and holds the samples in place.
} } } I have great LTSEM results using this mixture with unfixed single cell } } } culture and bacteria. The separate problem about the fine layer of salt, } } } (if the osmatic change is all right!) use larger amount of distilled water } } } to rinse for longer time.
Tony replies: } Use Osmium vapour to semi-fix the cells before plunging into water. } Osmotic shock is then reduced to minimum.
} Regards, } } Tony King } Product specialist } VG Microtech/ Polaron range } } Tel: +44 (0)1825 746251 } Fax: +44 (0)1825 768343 } } E&OE }
Best regards, steven E. Slap ******************************** Energy Beam Sciences, Inc. Adding Brilliance To Your Vision ebs-at-ebsciences.com http://www.ebsciences.com/ ********************************
Good afternoon, I've been asked by a student about possible fixation protocols for the analysis of Spisula solidissima (surf clam) larval development by SEM. The protocol she has been using has resulted in considerable shrinkage. She is fixing the material in 4% paraformaldehyde in buffered "sea water". She was unable to give me the exact reference at the time, but said it was by Longo. Any and all input would be greatly appreciated.
Thanks in advance.
Dwight Beebe E-mail: beebed-at-ere.umontreal.ca Institut de recherche en biologie vegetale Voice: 514-872-4563 Universite de Montreal FAX: 514-872-9406 4101, rue Sherbrooke est Montreal, Quebec H1X 2B2 Canada "Time flies like an arrow; fruit flies like a banana"
I am looking for a stain called "Crossmon trichome" (this may have been misprinted in the reference). Can anyone help me locate a supplier? I have tried the obvious big chemical supply companies.
To the Microscopy List, I've got some 30 um thick frozen dog pituitary sections which are showing punctate autofluorescent staining (in both Fitc and Rho channels), without antibodies. Does anyone have suggesstions on reducing this annoying autofluorescence, specific concentrations, time and temps would be appreciated.
Dear Scott, I have used high-strength epoxy (24 hour, not 5 minute hardening time) to prepare cross-sections of ion-implanted Gallium Arsenide. We were waiting for the M-610 to be delivered. It is slow but does not raise the temperature much in the thin layers. I had the shop make a small, parallel-jawed vise with teflon-lined jaws to clamp the sample in. These samples were dimpled, then ion-milled. At 12:47 PM 1/12/97 -0600, you wrote:
} I have a specimen preparation problem which some of you on the list may be able to help me with. } } I have been using M-BOND 610 to prepare my TEM cross-sectional samples with great success, but I am now worried that the elevated temperature curing (200C for two hours) is annealing the thin films I am examining(I am looking at copper thin films on a quartz substrate, which I sandwich between wafers of silicon for the cross sections). Has anyone had any good experiences using a room temperature adhesive for cross-sections which will be tripod polished and briefly ion milled? } } } F. Scott Miller Regards, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
1/97 SUMMER MICROSCOPY TECHNICIAN POSITION AVAILABLE
A three month (June, July, and August) position is open for a microscopy oriented technician at the Marine Biological Laboratory, Woods Hole, MA. We would like to attract someone with some knowledge of biological preparative techniques and experience in laser scanning confocal microscopy, TEM, SEM, and/or LM.
The technician will assist in the Central Microscopy Facility. The technician's duties will be to check out incoming investigators in the usage of our equipment and then to supervise its continuing usage and to perform contract work for investigators. This may include fixation, embedding, sectioning, scope use, darkroom work, etc. The technician will also provide routine maintenance.
This is a short term and scientifically rewarding position. Salary will be in the $7 to $9/hour range. Housing may be available to rent through MBL.
For more information, including a more detailed position description, please contact Louis Kerr at: MBL, 7 MBL Street, Woods Hole, MA 02543. Telephone, 508-289-7273; or at Email: lkerr-at-mbl.edu. Please apply to: Human Resources, MBL, 7 MBL Street, Woods Hole, MA 02543. or resume-at-mbl.edu.
An Equal Opportunity/Affirmative Action Employer/ Non-smoking workplace.
Louie Kerr Research and Education Support Coordinator Marine Biological Laboratory 7 MBL Street Woods Hole, MA 02543 508-289-7273 508-540-6902 (FAX)
We are looking for a powerful software to catalog, store and reteive images. We prefer something that is compatible with both PC and the MAC. Any suggestions?
__________________________________________ Rex A. Hess, Ph.D., Associate Professor, Director, Center for Microscopy and Imaging University of Illinois, Veterinary Biosciences, 2001 S. Lincoln, Urbana, IL 61802-6199 217-333-8933; FAX 217-244-1652; email: r-hess-at-uiuc.edu homepage-- http://www.cvm.uiuc.edu/HomePages/rhess/hesspage.html
We are contemplating digitizing our darkroom and seek any thoughts you might provide on scanners and printers. This is primarily an EM lab so we would be scanning standard 3.25" X 4.0" EM negs. and 4" X 5" Polaroid SEM negs.
We are considering multiformat film scanners, specifically the Nikon LS-4500AF and the Polaroid Sprintscan 45, and flatbed scanners, specifically the Microtek ScanMaker III and the UMax PowerLook 11.
Do you have any recommendations for neg. scanner vs flatbed scanner? Of the models listed, does anyone have any experience - good or bad?
We have also thought about the Leaf MicroLumina and understand that it is excellent. Is the MicroLumina's performance worth the price differential?
As far as a printer, we're basically set for dye-sub. printers but would like to get a laser printer for "routines". I've pretty much narrowed it down to the Lexmark OptraR plus with about 32 meg. of memory. Does this sound reasonable? Got any other recommendations.
Any input would be greatly appreciated. TIA for your help.
John
John G. Aghajanian, Ph.D. Worcester Foundation for Biomedical Research 222 Maple Avenue Shrewsbury, MA 01545 Phone: 508 842-8921 ext. 147 Fax: 508 842-9632 email: johna-at-sci.wfbr.edu
This is a rather important process that should be done very carefully. I devoted several pages to discussing methods for cleaning parts for vacuum systems in my book 'Vacuum Methods in Electron Microscopy' p.69-74. If you are using the standard top-entry type of holder, cleaning should be straightforward - scrub it thoroughly with Tilex Soap Scum Remover, rinse with hot running water, sonicate in a strong detergent solution, rinse with hot tap water, rinse with reagent grade isopropyl alcohol, dry with a gas blaster. If you are using a side entry stage you can use essentially the same procedure, but you must then be careful to avoid getting the solutions inside the holder if it is one that has provisions for manipulating the specimen. Often, enough cleaning can be done to get rid most contamination problems by sonicating just the end of the holder in isopropyl alcohol, then drying with a blaster. The latest method for these holders is Plasma Discharge Cleaning, and Southbay Technologies markets a device that is specially designed for this purpose. W. C. Bigelow (bigelow-at-umich.edu)
Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:313-763-4788; Ph:313-764-3321
There are many reasons for NOT using grease-base polishes for cleaning parts to be inserted into the interior of high vacuum sysstems (See Vacuum Methods in Electron Microscopy, Portland Press, pp. 69-74). Basically, this is the equivalent of taking a bath in a mud puddle. One principal reason for cleaning is to remove hydrocarbon materials from the surfaces of the parts, and so it makes no sense at all to use a greasey material to do the job. In addition, as noted by others, the grease and abrasive materials are likely to get embedded in cracks and crevice and then not be completely removed, whereupon they will act as a very effective source of contamination. Very effective cleaning can usually be accomplished simply by thoroughly scrubbing with one of the many modern detergent solutions formulated for use in the electronics inductry (see above reference) or with Tilex Soap Scum Remover (available in most supermarkets), rinsing with running hot tap water, ultra sonic treatment in a warm detergent solution, rinsing again with hot tap water, rinsing with reagent grade isopropyl alcohol, and drying with a gas blaster. If you find you need an abrasive in the initial stage to remove stubborn deposits (or if you feel you must enhance the surface finish) try using a bit of Comet Cleaner (the kind formulated for use on plastic tubs and showers, which wont seriously scratch most metals) and then rinsing with hot water, before the initial scrubbing step. This procedure involves no solvents other than water and isopropyl alcohol (a common constituent of rubbing alcohol, and therefor perfectly safe to use) and so no expensive or complicated safety procedures are necessary, and it usually does the job quite nicely. The Tilex Soap Sum Remover will even remove silicone oils from most metal surfaces, and I have also used it to remove spots of various kinds from clothing, grease spots from carpets and auto seat covers, and semi-dried paint from my hands after painting. Needless to say, it works great for its intended purpose of cleaning bathtubs, wash basins, shower curtains and shower tiles. (No commercial interest, it is just very handy stuff to know about) W. C. Bigelow (bigelow-at-umich.edu)
Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:313-763-4788; Ph:313-764-3321
I'm looking for a used EDX detector to interface to a Hitachi 2500 SEM, to use while upgrading the original Kevex Delta 3 Quantum system. Geometry is more important than make or model, but Kevex with or without thin window would be best. Please e-mail me with any possibilities and price.
A colleague asked if I could do EDXS for calcium deposits on the surface and/or in cells of histosections that are mounted, stained and coverslipped. It would mean removing the coverslip and mounting medium, and then get the surface really clean without loss of the region of interest (no pun intended). Is this the method to use or is there a better one and what would be the specifics of the method. Has anyone done this before? All I know is that the sections were stained with some sort of silver-type stain that is nonspecific for calcium but if present will show up as a dark body. The sections were not counterstained. Is there too much calcium in the glass that I wouldn't be able to see the particles against the background?
Thanks for any suggestions, they will be most appreciated.
A colleague here needs a used EDS detector, preferably Kevex, to fit a = Hitachi 2500 SEM. He tells me those that fit the Hitachi 2300-2400 models might also work. I = also need one or both of the video boards for a Kevex 8000 analyzer. = Anyone have some spares?
*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.* James J. McGee (jmcgee-at-sc.edu) Dept. of Geological Sciences University of South Carolina (803) 777-6300 (Office) Columbia, SC 29208 (803) 777-6610 (Fax)
We are looking for a powerful software to catalog, store and reteive images. We prefer something that is compatible with both PC and the MAC. Any suggestions?
__________________________________________ Rex A. Hess, Ph.D., Associate Professor, Director, Center for Microscopy and Imaging University of Illinois, Veterinary Biosciences, 2001 S. Lincoln, Urbana, IL 61802-6199 217-333-8933; FAX 217-244-1652; email: r-hess-at-uiuc.edu homepage-- http://www.cvm.uiuc.edu/HomePages/rhess/hesspage.html
----- End Included Message -----
Rex,
I use Aldus Fetch as a cataloging program for my Power PC. The images can be worked on with Photoshop on either PC or Mac. Image transfer is usually accomplished by ftp from one computer to another over a network. Others whom I know use it also like it.
Ed Basgall, PhD Res Assoc Dept. of Chemistry Surface Analysis Group Penn State Univ. 181 Materials Res. Inst. Bldg University Park, PA 16802
} I've been asked by a student about possible fixation protocols for } the analysis of Spisula solidissima (surf clam) larval development by SEM. } The protocol she has been using has resulted in considerable shrinkage. } She is fixing the material in 4% paraformaldehyde in buffered "sea water". } She was unable to give me the exact reference at the time, but said it was } by Longo. Any and all input would be greatly appreciated. } } Thanks in advance. } } } Dwight Beebe E-mail: beebed-at-ere.umontreal.ca
Have you tried (all together now) HMDS? [Hexamethyldisilizane]. I've had success with this with nudibranch veligers. Use a: 100% EtOH (3X washed)=} 3:1-1:1-1:3=} 100% HMDS (3X wash) change, drain off excess leaving specimens covered, and dry at 60 C. Do *everything* in a fume hood! But then soft little zooplankters like to shrink anyway. If you have access to one, you might be better off looking at fixed or fresh, hydrated specimens in an ESEM or variable-pressure scope tricked up to suck in water vapor; frozen hydrated specimens in a cryoSEM would be the other way to go. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
I hope you can post this postdoc position. Nina Allen
CALCIUM SIGNALING AND GRAVIPERCEPTION IN PLANTS
NCSU-NSCORT Postdoctoral Fellowships
Cell Biology-Imaging: POSTDOCTORAL POSITION is available immediately for the NASA Specialized Center of Research and Training (NSCORT) in gravitational biology. This is an opportunity to join a dynamic group of 12 project leaders and 5 postdocs studying the effects of altering calcium homeostasis on plant responses to gravity. The group is taking an integrated approach involving molecular, cellular, biochemical and physiological techniques. The specific project involves monitoring early changes in cellular calcium either by calcium ratio imaging and/or electrophysiology. Applicants do not require prior experience in plant biology but the calcium imaging applicant must have experience in calcium ratio imaging, image analysis, and microinjection. Electrophysiologists should have experience with either vibrating probes or patch clamping techniques as well as microinjection and computer analysis and be willing to collaborate with colleagues in the NSCORT as well as the National Vibrating Probe Facility at the Marine Biological Laboratory at Woods Hole, Massachusetts. Send curriculum vitae and names of three references to : Nina Stromgren Allen, Department of Botany, North Carolina State University, Raleigh, NC 27695-7612. Fax: 919-515-3436. Email: nina_allen-at-NCSU.EDU. NCSU is an Equal Opportunity Employer.
Nina Stromgren Allen Department of Botany Box 7612 North Carolina State University Raleigh, NC 27695-7612 Phone: 919-515-8382 (Office), 515-3525 (Lab), 515-2727 (Department Secretary) Fax: 919-515-3436
We are contemplating to buy a slow scan CCD camera for recording TEM CBED Kikuchi patterns and authomatically index them using Hough transform (amongst other things). This is to be part of a fully automated crystal orientation measurement facility, where "large" sample areas may be measured without user interaction.
The equipment is to be installed on a CM200. A 16 bit resolution is preferable (or eaven neccessary?). Are there anyone in the community who would like to share their experience on this matter with us? Any comments / advice will be grately welcomed.
Yours sincerely, Paul Baggethun.
============================= P.Baggethun (post-doc) Ecole des Mines de Saint-Etienne Centre SMS 158 Cours Fauriel F-42100 SAINT-ETIENNE, CEDEX 2 FRANCE =============================
Hi Folks, On the subject of image databasing raised by Rex Hess
We have had a lot of success using an inexpensive though very neat package called thumbs plus, you can down load it from any of the usual share ware or windows sites. It catalogs, does thumbnails, keywords, some basic image processing, works with a whole bunch of file formats, and in our case perhaps most importantly allows offline cataloging. we use CD's as our primary archive. This package provides a nifty offline catalog in which the CD title is seen which may be expanded to the entire directory structure together with thumbnails of the images. Older versions of the package got kind of slow with big databases (} 10K images) the current incarnation seems to remain pretty speedy even when loaded up with about 200 CDs plus continual updates of a large stack of networked drives. We are pretty happy with the package having tried several of the expensive, and inexpensive solutions
-- ======================================== Simon C. Watkins Ph.D. Associate Professor Director, Structural Biology Imaging Center Scaife 840 University of Pittsburgh Pittsburgh PA 15261
THis is a bit of an old saw but has anyone done a comparison of the currently available immersion oils wrt autofluorescence. Our light microscope platform is diverse (Zeiss, Nikon, Olympus) and slides etc travel from scope to scope which would lead to disastrous contamination problems if each 'scope had its own oil. We have been hanging on to Zeiss oil up to now , simply because we had a large bottle of the stuff. I have been a little unhappy with the levels of autofluorescence recently (prior to contamination ) and was looking for a change. Any ideas?
Simon
-- ======================================== Simon C. Watkins Ph.D. Associate Professor Director, Structural Biology Imaging Center Scaife 840 University of Pittsburgh Pittsburgh PA 15261
We are interested in buying a used TEM+EDX system. If you have, or know anyone who has one for sale, please send me a private email (we are willing to pay for the shipment).
Many thanks.
Redha Touaitia School of Engineering University of Northumbria at Newcastle Newcastle Upon Tyne NE1 8ST UK Tel : +44-191-227 36 14 email: r.touaitia-at-unn.ac.uk
I concur wholeheartedly. Thumbs Plus is fast, easy to learn, easy to use, flexible....buy it. Our R&D comuting department is considering the network-licensed version as a standard platform for image cataloging, in place of Microsoft Access and other high-power databases. AND for all you NIH Image users, a Mac version is planned.
Cerious Software can be found on the web at: http://cerious.catalogue.com/index.html
I have no financial or other interest (other than hoping the product continues to improve) in Cerious Software. ------------------------------------------------- Harold J. Crossman OSRAM SYLVANIA INC. Lighting Research Center 71 Cherry Hill Dr. Beverly, MA 01915 Phone: (508) 750-1717 E-mail: crossman-at-osi.sylvania.com
Our web sites: www.sylvania.com www.siemens.com --
Dear all, I have been asked to put the following job announcement on the listserver.
} Electron Microscopy Postdoctoral Position } Rutgers University } } The Ceramics Department at Rutgers University is seeking a postdoctoral } associate with an electron microscopy background. The candidate should be } interested in breaking new ground in the characterization of multicomponent } powder mixtures using a fully digital FE-SEM coupled with position-tagged } spectroscopy (PTS). PTS is a novel EDS method that can provide interaction } volumes as small as 50 nm and full spectrum scans within each pixel. The } candidate will work within a research group focused on understanding the } relationship between powder characteristics and the experimental and } theoretical achievable level of homogeneity in powder mixtures. Microscopy } work will be correlated with a state of the art mixedness simulation model } known as the concentric shell model of mixedness. The candidate should be } able to work within a team that has strong theoretical as well experimental } orientations. Candidates should demonstrate their ability to conduct } cutting-edge research in microscopy as well as effectively communicate with } others. The position is immediately available with a highly competitive } salary dependent on the candidate's qualifications and includes full health } care benefits. Candidates should submit their curriculum vitae, three } letters of reference, relevant publications and their anticipated starting } date by February 15, 1997 to: } } Richard E. Riman } Department of Ceramics } Rutgers, The State University of New Jersey } P.O. Box 909 } Piscataway, NJ 08855-0909 } } 908-445-4946 } 908-445-6264 (fax) } riman-at-erebus.rutgers.edu
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Ian MacLaren, Tel: (44) (0) 121 414 3447 IRC in Materials for FAX: (44) (0) 121 414 3441 High Performance Applications, email: I.MacLaren-at-bham.ac.uk The University of Birmingham, http://sun1.bham.ac.uk/I.MacLaren/ Birmingham B15 2TT, England. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MICROSCOPY & ANALYSIS is widely circulated among microscopists in the UK, Europe and the USA. Our editorial articles cover a broad spectrum of applications, techniques and instrumentation in all branches of microscopy and related analytical methods.
As I posted a few months back, we intend to start a "Questions and Answers" feature. Originally this was scheduled to appear in our January issue, but for various reasons was delayed. It will now appear in the March issue.
If you have any technical or scientific questions in the field of microscopy and related analysis that you would like to put to a large, expert readership, please e-mail them to me.
Regards,
--------------------------------------------------------------- Dr L. P. Stoter Technical Editor, MICROSCOPY & ANALYSIS Technesis 17, Rocks Park Road email: LPS-at-teknesis.demon.co.uk Uckfield, E. Sussex Phone: +44 (0)1825 766911 TN22 2AT Fax: +44 (0)1825 766911 United Kingdom ---------------------------------------------------------------
Add my vote to everyone elses regarding thumbs plus. Bang for buck, we have not found anything better.
Jay Jerome ************************************************************** * aka: W. Gray Jerome * * Dept. of Pathology * * Bowman Gray School of Medicine of Wake Forest University * * Medical Center Blvd * * Winston-Salem, NC 27157-1092 * * 910-716-4972 * * jjerome-at-bgsm.edu * **************************************************************
I am also in the search for an image archiving solution. I've played with several packages that work nicely as a "local" solution, but need to expand the scope to include accessability (and searchability) via our corporate intranet.
Specifically, is anyone aware of, or have experience with, an ODBC complient application which will run on an NT based server, that has an API to NETSCAPE? The local input application should be PC or MAC, and should handle multimedia as well as still images.
Thanks in advance,
**************************************** Don Steele Steele-at-KRDC.INT.Alcan.Ca Alcan International Kingston Research and Development Centre (613) 541 - 2145 ****************************************
I did do a test of immersion oil autofluor and found Nikon to be the lowest.
Bob Morphology Core U of Washington
On Wed, 15 Jan 1997, simon watkins wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } -- [ From: simon watkins * EMC.Ver #2.5.02 ] -- } } Hi Folks: } } THis is a bit of an old saw but has anyone done a comparison of the } currently available immersion oils wrt autofluorescence. Our light } microscope platform is diverse (Zeiss, Nikon, Olympus) and slides etc travel } from scope to scope which would lead to disastrous contamination problems if } each 'scope had its own oil. We have been hanging on to Zeiss oil up to now } , simply because we had a large bottle of the stuff. I have been a little } unhappy with the levels of autofluorescence recently (prior to contamination } ) and was looking for a change. Any ideas? } } Simon } } -- } ======================================== } Simon C. Watkins Ph.D. } Associate Professor } Director, Structural Biology Imaging Center } Scaife 840 } University of Pittsburgh } Pittsburgh PA 15261 } } tel: 412-648-3051 } fax: 412-648-8330 } ========================================= } } }
I concur with Simon's opinion below. I've been using a couple of versions of ThumbsPlus for over a year. In addition to making image databases, I use it to review my work at the end of the day. In combination with an Epson color ink jet printer (e.g. Stylus Pro or 500) I can perform a "sanity" check on my recent data in a very inexpensive manner.
} Return-Path: {Microscopy-request-at-Sparc5.Microscopy.Com} } Errors-To: Microscopy-request-at-Sparc5.Microscopy.Com } X-Sender: zaluzec-at-microscopy.com } Date: Wed, 15 Jan 1997 22:52:05 -0500 } To: microscopy-at-Sparc5.Microscopy.Com } From: simon watkins {swatkins-at-pop.pitt.edu} (by way of Nestor J. Zaluzec) } Subject: Re: catalog images } Errors-To: Microscopy-request-at-Sparc5.Microscopy.Com } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
I have had a few requests for a location for thumbs plus, you can download the demo from www.cerious.com
thanks
Simon
-- ------------------------------------------------- Simon C. Watkins Ph.D Associate Professor Director SBIC University of Pittsburgh Pittsburgh PA 15261 tel 412-648-3051 fax 412-648-2004 -----------------------------------------------
Probably a no-brainer :)...does anyone have any suggestions as to how I can stain agar blocks for embedding in LR White? So I can find them again in the final block? So far I've only tried Toluidine Blue - didn't work. I have some Coomassie-agar in the works right now, but it is clearing, too. Multiple suggestions are MORE than encouraged...because I'll ultimately need something that will stain the agar without messing up my antigens. Sigh. Thanks! Tamara CSHL, NY
We would like to know if anyone can suggest methods for preparing liposomes for SEM imaging other than those requiring freeze-fracture or other cold-stage techniques. Specifically, are there other methods for drying/preparation of a liposome suspension that can avoid dissolving the liposomes in the process. ******* ******* ******* A similar request was posted on this listserver by a Donna Turner {dturner-at-bcm.tmc.edu} on 12/20/96. The question was:
"I need information regarding processing for thin-sectioning of liposomes. These samples are used for Cyclosporin A treatment (inhalation) of lung tumors. I will also be using negative staining. Suggestions please!"
Thanks for any help with either of these questions -- Gerald Harrison
Can someone please enlighten me as to the difference in theory and practice between formalin and formaldehyde (presumably made up as a buffered solution) for tissue fixation. Dave
Dr. David Knecht Department of Molecular and Cell Biology University of Connecticut U-125 Storrs, CT 06269 Knecht-at-uconnvm.uconn.edu
Hi All, I recently got a software package for pc that is called "PAX IT". I haven't fully investigated all it's capabilities, but it seems like a very user friendly and well organized software. I am not sure about the MAc/Pc transfer, but you could ask them Midwest Information systems - tel. 847 455 0450.
cheers
Lucio
Dr.Lucio Mule'Stagno MEMC Electronic Materials Inc University of Missouri -St.Louis Silicon Materials Research Group Physics Dept., 501 Pearl Dr., 8001 Natural Bridge rd., St.Peters, St.Louis MO 63376 MO 63121 tel: 314 279 5338 314 516 5931/3 fax: 314 279 5363 314 516 6152 email: lmulestagno-at-memc.com luciom-at-newton.umsl.edu
On Wed, 15 Jan 1997, Ed J. Basgall wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } } ----- Begin Included Message ----- } } We are looking for a powerful software to catalog, store and reteive } images. We prefer something that is compatible with both PC and the MAC. } Any suggestions? } } } __________________________________________ } Rex A. Hess, Ph.D., Associate Professor, } Director, Center for Microscopy and Imaging } University of Illinois, Veterinary Biosciences, 2001 S. Lincoln, Urbana, } IL 61802-6199 } 217-333-8933; FAX 217-244-1652; email: r-hess-at-uiuc.edu } homepage-- http://www.cvm.uiuc.edu/HomePages/rhess/hesspage.html } } ----- End Included Message ----- } } } Rex, } } I use Aldus Fetch as a cataloging program for my Power PC. The images can } be worked on with Photoshop on either PC or Mac. Image transfer } is usually accomplished by ftp from one computer to another over a network. } Others whom I know use it also like it. } } Ed Basgall, PhD } Res Assoc } Dept. of Chemistry } Surface Analysis Group } Penn State Univ. } 181 Materials Res. Inst. Bldg } University Park, PA 16802 }
POST-DOCTORAL RESEARCH ASSOCIATE Lehigh University
A post doctoral research associate position is available in the Department of Materials Science and Engineering at Lehigh University. The appointment is initially for one year, renewable for a second year. It involves an analytical electron microscopy study of boundary segregation in commercial aluminum alloys. A PhD in materials science and engineering with strong AEM background (X-ray and EELS) is essential: VG experience is highly desirable.
Please send resume and names and addresses of three referees to:
Dr. David B. Williams Department of Materials Science and Engineering Lehigh University 5 East Packer Avenue Bethlehem, PA 18015
Lehigh University is committed to recruiting, retaining, and tenuring women and minorities.
Sharon L. Coe Department of Materials Science & Engineering 5 East Packer Avenue Lehigh University Bethlehem, PA 18015 610/758-5133 e-mail: slc6-at-lehigh.edu
I could use some help on identifying an ultramicrotome recently acquired from our life sciences department. Unfortunately, the previous owners did not have the instruction book for the instrument or any clue on how to use it. It was made by Cambridge and I believe the model is a Huxley ultramicrotome. I do have the serial number (sort of) written on the side of the instrument. Any help with locating the manufacturers or an instruction book would be greatly appreciated.
Any references on techniques for using the microtome with ultra-hard materials and composites would also be appreciated. Am I going to h-e-double-hockey-sticks for using a life sciences microtome in materials science?
Thanks,
Brian Gorman Graduate Research Assistant University of Missouri - Rolla Dept. of Ceramic Engineering 225 McNutt Hall Rolla, MO 65409
Tamara, We have been able to stain agarose (as well as some plant tissue) very well with fast green. Best results are to stain when the tissue is in 100% etoh. You can make a very concentrated solution of fast green (around 7% I think) and add a few ul per ml to the vial containing samples. This staining survives subsequent infiltration into methacrlate resins very well. Trouble is, if you are going through acetone, fast green is really not to solulble in acetone. I have not found a very good stain to use with acetone dehydrations, although Alizarin red isn't bad. Hope this helps, Tobias
Tamara, We have been able to stain agarose (as well as some plant tissue) very well with fast green. Best results are to stain when the tissue is in 100% etoh. You can make a very concentrated solution of fast green (around 7% I think) and add a few ul per ml to the vial containing samples. This staining survives subsequent infiltration into methacrlate resins very well. Trouble is, if you are going through acetone, fast green is really not to solulble in acetone. I have not found a very good stain to use with acetone dehydrations, although Alizarin red isn't bad. Hope this helps, Tobias
"Can someone please enlighten me as to the difference in theory and practice between formalin and formaldehyde (presumably made up as a buffered solution) for tissue fixation. Dave"
formalin is made by bubbling formaldehyde gas thru water until saturation (37% w/w or 40% w/v). Many (all?) commercial formalins contain 6-15% methanol to prevent polymer formation. Even with the methanol, polymers form over time. The different polymers presumably mean "different" fixation reactions are occuring. The formation of formic acid over time can cause the presence of "formalin pigment" due to reaction with hematin in blood rich tissues. Electron microscopists never (or virtually never) use formalin and use instead freshly depolymerized paraformaldehyde (heat granules to 60 C but not hotter, with stirring, then add a drop or two of 1 N NaOH - if you need a detailed protocol, e-mail me and I will send you one). One of the most common questions I get asked is whether it will make any difference in someone's LM immunocytochemical study to use freshly depolymerized formaldehyde as opposed to formalin. I am sure in many cases it will not make a difference but that there are undoubtedly examples where it does make a difference. I always make my formaldehyde fresh the day I use it.
Tom
Thomas E. Phillips, Ph.D. Associate Professor of Biological Sciences Director, Molecular Cytology Core Facility 3 Tucker Hall University of Missouri Columbia, MO 65211 (573)-882-4712 (voice) (573)-882-0123 (fax)
Formaldehyde is a gas that is bubbled through water to give a 37-40% solution (saturated) sold as "formaldehyde". One part of this to nine parts water gives "formalin" or "10% formalin" (which is really 3.7 to 4.0% formaldehyde). When one makes a paraformaldehyde fixative it is often 4g paraformaldehyde per 100 ml of buffer.
Geoff (mcauliff-at-umdnj.edu) -- *************************************************************** Geoff McAuliffe, Ph.D. Neuroscience and Cell Biology Robert Wood Johnson Medical School 675 Hoes Lane Piscataway, NJ 08854 voice: (908)-235-4583; fax -4029 e-mail: mcauliff-at-.umdnj.edu ***************************************************************
I seem to recall using dilute eosin, slightly acidified to keep it from leeching out, to stain agar blocks prior to embedding. Don't know what it might do to antigens, though.
Geoff (mcauliff-at-umdnj.edu) -- *************************************************************** Geoff McAuliffe, Ph.D. Neuroscience and Cell Biology Robert Wood Johnson Medical School 675 Hoes Lane Piscataway, NJ 08854 voice: (908)-235-4583; fax -4029 e-mail: mcauliff-at-.umdnj.edu ***************************************************************
I know that this isn't specifically Microscopy but there may still be some strong interest.
Please send any questions or replies directly to john Vankat not myself.
John Vankat wrote: } } Assistant Professor, Botany } Miami University-Middletown } } The Department of Botany at Miami University seeks applicants for a } tenure-track position on the Middletown campus beginning August 1997. } Duties include teaching (occasionally at off-campus facilities) } introductory undergraduate lecture and laboratory courses in Botany } and participating in interdepartmental courses in biology. Other } responsibilities include service appropriate to the Regional Campus } mission and development of a scholarly program that involves } undergraduates. Position requires Ph.D. in Botany or closely related } discipline and experience in and commitment to undergraduate teaching } and advising. Send letter of application, one page statement of } teaching philosophy, description of teaching experience, curriculum } vitae, and three letters of recommendation to Dr. John L. Vankat, } Search Committee Chair, Department of Botany, Miami University, } Oxford, OH 45056. Review of applications begins February 3, 1997. } Phone: (513) 529-4200; Fax: (513) 529-4243; e-mail: } JLVANKAT-at-MIAMIU.MUOHIO.EDU } Miami University does not discriminate on the basis of sex, race, } color, religion, national origin, disability, age or sexual } orientation in its employment policies.
This message has also been posted to the confocal listserver.
Dear fellow microscopists,
Can someone enlighten me on the potential pitfalls of RI mismatch between coverslip and immersion oil. I am working with someone who must grow his cells on Aclar coverslips (RI = 1.435). We are mounting the specimens in Vectashield (RI = 1.4577) and are using Zeiss oil (RI = 1.515). We are trying to do confocal reconstructions of fluorescently tagged (FL and RH) mineral aggregates in these cultures (approx. 10-20 um} thick) to visualize their substructure. To do this we are using 100X oil immersion lens at Zoom 4 on a Leica TCS-NT confocal. What sorts of aberrations could I expect in the reconstructed images?? Should I use an oil with a lower RI? A related question: Most of the fluorescent specimens I work with have glass coverslips and are imaged with oil immersion objective lenses (consistent RI), but are mounted in Vectashield (Lower RI) or similar anti-photobleach medium. What problems does this pose for confocal imaging??
} Can someone please enlighten me as to the difference in theory and practice } between formalin and formaldehyde (presumably made up as a buffered } solution) for tissue fixation. Dave } Formaldehyde is a gas which, when dissolved to a final concentration of 40% in water, is termed formalin. Typically, commercially prepared formalin contains "stabilizers" such as methanol or calcium carbonate (chalk) which slow down the polymerization of the aldehyde groups. Formalin at 4-10% aqueous (buffered or unbuffered) may be suitable for preserving bulk specimens (chunks of liver, whole brains, etc) and may be suitable for preserving tissues for histological studies by light microscopy. For highest quality (ultrastructural studies, for example), it is best to prepare the formaldehyde by depolymerizing paraformaldehyde using a combination of heat and aldehyde (such as KOH). I can provide details, if you need this. Usually, one prepares an 8-10% aqueous solution of formaldehyde and then mixes this with a double strength buffer (phosphate buffer at pH 7.4 for mammalian tissues, for example) to obtain a buffered formaldehyde solution. Many buffers may be used and I can forward more info if you need it.
#################################################################### John J. Bozzola, Ph.D., Director Center for Electron Microscopy Southern Illinois University Carbondale, IL 62901-4402 U.S.A. Phone: 618-453-3730 Fax: 618-453-2665 Email: bozzola-at-siu.edu Web: http://www.siu.edu/departments/shops/cem.html ####################################################################
Due to policy and politics, our EM facility does not teach biological TEM "from scratch" (although we do teach SEM from scratch). We require users of most of our instruments to have had a course or prior experience. Right now there is no other place to learn TEM in our island state, and there is some pressure on us to teach several people. I am completely willing and able. However, in order to deal with the situation, we need to be able to 1) estimate about how much it would cost to train someone (or, more likely, a group of 4) to try to cover our actual costs and/or 2) where could these people go to take a short/intensive course (say, 3-5 weeks) and how much would that cost? There have been discussions here before about mixing new EM students with hard-core research interests. Up until now I've managed to keep it from being a problem, but now I am soliciting advice!
Aloha, Tina
http://www.pbrc.hawaii.edu/bemf/microangelo Text coming soon! **************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
THis is a bit of an old saw but has anyone done a comparison of the currently available immersion oils wrt autofluorescence. . . . Simon ========================================= We supply the full range of Cargille immersion oils. Cargille know very well the properties of their oils and different grades are available for different purposes. Sufficient details for most people can be found in our on-line catalogue on page I1. The most commonly used oil is type B, which has "ideal" optical properties at average viscosity "low" auto-fluorescence. Type DF has "ideal" optical properties, "very low" auto-fluorescence but is a little more expensive. Type FF has "zero" auto-fluorescence with good (imperfect) optical properties at the same price as the DF. Labs using fluorescent and normal light microscopes and do not have several litre requirements of immersion oils annually may be best advised to use the DF type only. If they, however, require zero auto-fluorescence than it would be best to mark the bottles clearly and keep separate supplies.
As stated, we have a (small) interest in immersion oils. Jim Darley
Probing & Structure (Microscopy Supplies & Accessories) PO Box 111, Thuringowa QLD 4817 Australia
Phone +61 77 740 370 Fax: +61 77 892 313 A great microscopy site: http://www.ultra.net.au/~pns/
I am presuming you have some sort of tissue in the agar blocks. I have been using agar to encapsulate the tissue ( in most cases suspended cells). If you stain the agar with 1% eosin B (prepared in 100% alcohol) for about 5 to 10 mints and then rinse in 100% alcohol and then start the infiltration with LRWhite. I have had no problems so far with tissue loosing the antiginicity. If you need more details contact me.
Fellow microscopists, just an addition to the image archiving discussion: I use a similar program Graphic Workshop from Alchemy Mindworks, Beeton ON Canada LOG 1AD www.mindworkshop.com I had previously looked at the demo. version of Thumbsplus, and found it very similar, having purchased one, found no reason to migrate. Does anyone have a comment on relative capabilities? I am not connected with, or have any interest in either company. greetings to all from 37 oC (100 oF) Rio de Janeiro. Prof.Walter A.Mannheimer Metallurgy and Materials Engineering Federal University of Rio de Janeiro POBox 68505 21945 Rio de Janeiro, Brazil Voice +5521 280-7443 (Dept.office) +5521 590-0579 (direct) Fax +5521 290-6626 Email: wamann-at-metalmat.ufrj.br
} Can someone please enlighten me as to the difference in theory and practice } between formalin and formaldehyde ... } A saturated aqueous solution of formaldehyde contains (nominally) 37% formaldehyde. Such a solution is referred to as a 100% formalin solution. (A 10% formalin solution would contain ~3.7% formaldehyde.)
The presence or absence of other components (such as buffers) is irrelevant, other than affecting the final concentration of formaldehyde. } Cheers.
Don ______________________________________________________________________ Donald L. Lovett e-mail: lovett-at-tcnj.edu Assoc. Professor, Dept. of Biology voice: (609) 771-2876 The College of New Jersey * fax: (609) 771-2674 Trenton, NJ 08650-4700
(* formerly Trenton State College; please note our new name)
We use Osmium to stain culture cells in agar, before we embed, then you can cut out the most concentrated area of cells to put in plastic.
Cheri Owen Detroit Neurotrauma Institute Detroit, Mi (313)577-4648
On Thu, 16 Jan 1997, Tamara Howard wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } Probably a no-brainer :)...does anyone have any suggestions as to how I can } stain agar blocks for embedding in LR White? So I can find them again in } the final block? So far I've only tried Toluidine Blue - didn't work. I } have some Coomassie-agar in the works right now, but it is clearing, too. } Multiple suggestions are MORE than encouraged...because I'll ultimately } need something that will stain the agar without messing up my antigens. } Sigh. } Thanks! } Tamara } CSHL, NY } } }
I needed to stain agar several years ago. Rather than stain it, I found it better to incorporate a colored microsuspension into it. Blue dextran works fine...its used to visualize the solvent front in column chromatography and gel filtration. Its a high mw polysacharride, much like agar and is virtually innocuous. Sigma carries it.
-=W.L. Steffens=- Department of Veterinary Pathology College of Veterinary Medicine University of Georgia http://www.vet.uga.edu/wls/steffens.html
} } } A saturated aqueous solution of formaldehyde contains (nominally) 37% } formaldehyde. Such a solution is referred to as a 100% formalin solution. } (A 10% formalin solution would contain ~3.7% formaldehyde.) } } The presence or absence of other components (such as buffers) is } irrelevant, other than affecting the final concentration of formaldehyde. } }
I am afraid I strongly disagree with this statement. Some buffers can precipitate Ca2+ ions (e.g., PO4). The lack of Ca2+ in the fixative is well known to affect preservation. Some buffers with free amine groups can interact with the fixative. The presence of alcohol or other preservatives in commercial formalins could be expected to cause differences in immunoreactivity in some instances. I have seen some commercial formalin stocks that contained fluorescent impurities (tho this may have been contamination by users).
Thomas E. Phillips, Ph.D. Associate Professor of Biological Sciences Director, Molecular Cytology Core Facility 3 Tucker Hall University of Missouri Columbia, MO 65211 (573)-882-4712 (voice) (573)-882-0123 (fax)
I have also used Graphics Workshop. I like to use it more for "manipulating" images. In that respects, use it as competition for commercially available graphics packages like Corel. I use Thumbs Plus primary for image databases (thumbnail subdirectories and contact sheets), archiving and quick looks at my data. I find Thumbs Plus to be much faster and easier to use for those operations.
At 11:21 AM 1/17/97 EST3EDT, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
I would like to further the discussion on plasma cleaning, the need to clean specimen holders, and cleaning Be holder components. In the past I have found it extremely beneficial to pre-clean the TEM specimen holder from the vacuum o-ring to the tip. Although no one admits to touching the specimen holder, it does occur. In fact, after a few minutes of plasma cleaning, fingerprints become quite apparent on the specimen holder. I've also seen o-ring grease wind up on the shoulder of the rod.
In addition, specimen holders are often times stored in less than ideal conditions and surface contamination becomes inevitable. A recommended solution is to store the specimen holder under vacuum (oil-free) when not in use.
Another cause of specimen holder contamination is from adhesives which adhere to the specimen holder's clamping mechanism. Plasma cleaning with the clamping mechanism open is quite effective in removing this contamination. With the plasma flow being multi-directional, even hard to access areas of the specimen holder are cleaned.
The Be situation raises a much larger issue when discussing plasma. All types of plasma are not equal. Depending on the plasma generation system, high energy (} 100 eV) ions can be created. At this level, ion impingement results in the sputtering of the specimen, specimen holder, plasma chamber walls, and electrodes, if they too are immersed in the plasma.
The critical need for applying plasma to TEM specimens is to produce a plasma of sufficiently low energy so that it is below the threshold required to break a molecular bond (approximately 35 volts). One acceptable means of generating low energy ions is with a high frequency, inductively coupled plasma, whereby the electrodes are located external to the plasma chamber. As long as the ion energy is sufficiently low, plasma cleaning can occur without the risk of sputtering Be.
We have conducted measurements on the ion energies in our plasma cleaner and found them to be, under given conditions, in the 12-15 eV range, well below the sputtering threshold. In this energy range, a chemical reduction of the carbonaceous material occurs without altering the material's structure.
I hope that this information is helpful. Do not hesitate to contact me directly with any specific questions.
Kind regards,
Paul E. Fischione
E.A. Fischione is the manufacturer of the Model 1400 Plasma Cleaner and Vacuum Storage Containers.
It sounds like you've come across an old gravity-powered Huxley microtome. The specimen arm was lifted (and advanced) by a lever. When released, gravity pulled the arm down its cutting stroke, the speed of which was controlled by a variable oil-filled dashpot. Friction on the block-face had to be kept at a minimum so that it would not overcome the falling arm. You were limited to a very small block face and very thin sections. I suspect that it might have trouble with hard materials. If its all there, it should work, because it only had about 2 moving parts.
-=W.L. Steffens=- Department of Veterinary Pathology College of Veterinary Medicine University of Georgia http://www.vet.uga.edu/wls/steffens.html
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Gerald,
Years ago I processed synaptosomes for thin section EM by "packaging" them in tiny agar tubes; I would try to do the same with your liposome preps.
Start with a 5% agar solution at ~60 degrees; thin down if tube walls are too thick. Dip a glass micropipet (type used for hematocrits) into the agar, cool over ice and slide the agar off the pipet with your fingers onto a cool wax sheet (sitting on ice). Cut the tube into bits ~0.5 cm long. Put a drop of your material onto the wax, pick up the tube and fill by touching to the drop. Seal with just-molten agar; trim off the "dumbbell" ends with a razor and process the filled tubes as you would a piece of tissue. Issues are the finding the right concentration of agar to yield some tension in the walls of the tube but yet thin enough for good permeability. Temperature may be tricky with liposomes.
WANTED: MONOCULAR HEAD or ADAPTER (that will fit INSIDE the binocular eye-piece tube) for CARL ZEISS GFL microscope to enable me to set up for microphotography. Adapter must be able to take a standard T-mount for a 35mm camera. Hopefully, you have an item of this sort gathering dust and can let it go at a very low price (plus shipping). Thank you. E-mail: bobcat54-at-aol.com
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Dear Fellow Microscopists, I'm looking for a full time technician position in a EM lab. I possess an appropiate educational background that match most of requesting in regard to the employment at EM laboratory. I have an EM Technician Certificate (1 yr. postgraduate program at Seneca College, Toronto, Canada)+ M.Eng. degree from Technical Academy of Agriculture, Faculty of Zootechny, Olsztyn,Poland. In addition, the EM program from Seneca College, Toronto gave many students untill closing hands on experience and theoretical knowledge in operation of TEM-SEM including all related techniques of biological specimen preparation essential to subsequent EM observation. My career objective is to become one of you with wide variety of preparation techniques in a biological field of EM. $ Any assistance you might be able to offer will be greatly appreciated or you need the further information about me just replay for this message. FOR ALL OF YOU I WISH A HAPPY & PROSPEROUS 1997! Andrew Kuczynski E-mail: 102137,1277-at-compuserve.com *************************************************************************** "While my name maybe is foreign to you, our language is the same and our backgrounds are similar." ***************************************************************************
I'm about to open up for the first time the diff pump in the carbon coater which I inherited as a going concern some 8 years ago. I suspect that the fluid in it is silicone, possibly DC 704, the one thing I do know is that it'll be pretty dirty. Does anyone know an infallible way to test very used diff pump fluid to ascertain whether it is a silicone or not?
cheers
Ritchie
Ritchie Sims phone: 64 9 3737599 ext 7713 Department of Geology fax: 64 9 3737435 University of Auckland Private Bag 92019 Auckland New Zealand
I am trying to find a way to measure and compare the relative intensity or brightness (?) of images (photomicrographs) of fluorescent labeled cells.
I have NIH Image as well as Photoshop and Excel. Would it be possible to make these types of measurements using these programs ? Is there another program you would recommend ?
What I am doing more specifically, is labeling cells at different micromolar concentrations of the fluorescent marker PKH26, then putting the cells into tissue culture flasks. I will then take slide photographs os the the flasks under magnification and fluorescent illumination at different points in time to assess the falloff in flurescence. I have the capability of making scans of the slides.
Thank you very much for your time,
David Fox, MD
************************** David Fox, MD Fellow in Vascular Surgery Loyola University Medical Center
For over 15 years now I have stored stages in slightly over pressurized dry Nitrogen environment using the N2 gas which vents off of LN2 tanks here at ANL. The N2 is directed into a simple plexiglass storage boxes with simple seals on the doors. These can be purchased from all the standard Microscopy Supply Houses. It is my experience that vacuum storage is rarely necessary and I've never seen documented evidence to show vacuum storage of TEM stages reduces contamination.
Having said this I do store a few stages in mild vacuum, but for very different reasons. The exception here, are some old Gatan LN2 & LHe stages we have here at ANL, which use microscope vacuum to achieve insulation. These (very) old models evacuated an outer insulating chamber of the cooling dewar by pumping on it via the microscope column using a small hole judiciously placed on the "column side of the o-ring seal". Leaving these stages in air always increases the pump down time when the stage is inserted into the microscope, presumably due to water vapor collecting in the chamber. Gatan has since redesigned their stages to remove this problem, however, I still use these stages as they continue to work. In this case the stages are stored in a simple chamber pumped down to ~ 10 mT using any RP. They are leaked back to ATM using N2 to make sure H2O vapor does not collect in the insulating dewar. I have never seen evidence of contamination of specimens which can be attributed to the stage being stored in a standard RP system, when the RP is properly operated. Of course, if you screw up and backstream oil into the system then all bets are off, however, that is a simple thing to avoid by good laboratory practice.
Our old Edwards 12E6 from 1966 was overhauled, upgraded etc. in 1981 and charged with 100 ml Edwards Silicone 704/F4. It reaches 1x10-4 torr during a normal day and 1x10-5 torr when cryo activities are going on. It is used for cleaning jobs and carbon filming. Not great maybe but the figures have held constant since the beginning. A while ago I intended opening it up again (it used to be an annual event pre-1976 with my predecessor) but on his retirement, time became more precious.
I intended opening it up a few years ago because a young technician came and said 'Keith, I think something might be wrong with the coating unit because there is smoke coming out the back' !! It turned out that the system was pumping in hi-vac mode and she had opened the air inlet! It was oil mist and I guessedthat the oil charge had by then disappeared. But no, it still runs. You've pricked my conscience! But those old units run and run!
With best wishes
Keith Ryan Plymouth Marine Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, England
Hi All For teaching purposes to show simple diffraction patterns and tilting thereoff, as well as to demonstrate twinning we chose the old route of preparing thin (20nm) gold crystal by by evaporating firstly Ag then Au on air cleaved NaCl at 400 to 450 degrees C (10-5 torr). We experience a few problems to get reproducible crystals: 1. Sometimes the Ag surface turn whitish in stead of silver. 2. The Ag does not completely dissolve in nitric acid (various concentrations tried...).
Can somebody help or refer me to literature on the subject or maybe suggest other routes for simple preparation of such demonstrating foils?
Thanks in advance
Sara Prins Surface and Structure Analytical Services Division for Material Science and Technology CSIR PO Box 395 Pretoria 0001, South Africa +27+12+8413974 sprins-at-csir.co.za
} I recently received the following request from a non-microscopist } colleague: } } } Do you have any current information about formaldehyde & cancer? } } We're looking for publications/documentation
Here're the most recent refs from a lit. search I did a while ago:
Authors Anonymous. Title Formaldehyde. [Review] Source IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. 62:217-375, 1995.
Authors Hansen J. Olsen JH. Title Formaldehyde and cancer morbidity among male employees in Denmark. Source Cancer Causes & Control. 6(4):354-60, 1995 Jul.
Authors McLaughlin JK. Title Formaldehyde and cancer: a critical review. [Review] Source International Archives of Occupational & Environmental Health. 66(5):295-301, 1994.
Authors Sterling TD. Weinkam JJ. Title Mortality from respiratory cancers (including lung cancer) among workers employed in formaldehyde industries [see comments]. Source American Journal of Industrial Medicine. 25(4):593-602; discussion 603-6, 1994 Apr. Comment in: Am J Ind Med 1995 Feb;27(2):301-5
Authors Marsh GM. Stone RA. Esmen NA. Henderson VL. Title Mortality patterns among chemical plant workers exposed to formaldehyde and other substances [see comments]. Source Journal of the National Cancer Institute. 86(5):384-6, 1994 Mar 2. Comment in: J Natl Cancer Inst 1994 Oct 19;86(20):1556-8
Authors Gardner MJ. Pannett B. Winter PD. Cruddas AM. Title A cohort study of workers exposed to formaldehyde in the British chemical industry: an update. Source British Journal of Industrial Medicine. 50(9):827-34, 1993 Sep.
Authors Partanen T. Title Formaldehyde exposure and respiratory cancer--a meta-analysis of the epidemiologic evidence. Source Scandinavian Journal of Work, Environment & Health. 19(1):8-15, 1993 Feb.
Authors Luce D. Gerin M. Leclerc A. Morcet JF. Brugere J. Goldberg M. Title Sinonasal cancer and occupational exposure to formaldehyde and other substances. Source International Journal of Cancer. 53(2):224-31, 1993 Jan 21.
Authors Marsh GM. Stone RA. Henderson VL. Title Lung cancer mortality among industrial workers exposed to formaldehyde: a Poisson regression analysis of the National Cancer Institute Study. Source American Industrial Hygiene Association Journal. 53(11):681-91, 1992 Nov.
Authors Marsh GM. Stone RA. Henderson VL. Title A reanalysis of the National Cancer Institute study on lung cancer mortality among industrial workers exposed to formaldehyde. Source Journal of Occupational Medicine. 34(1):42-4, 1992 Jan.
Authors Holmstrom M. Lund VJ. Title Malignant melanomas of the nasal cavity after occupational exposure to formaldehyde [see comments]. Source British Journal of Industrial Medicine. 48(1):9-11, 1991 Jan. Comment in: Br J Ind Med 1993 Aug;50(8):767-8
Authors Partanen T. Kauppinen T. Hernberg S. Nickels J. Luukkonen R. Hakulinen T. Pukkala E. Title Formaldehyde exposure and respiratory cancer among woodworkers--an update. Source Scandinavian Journal of Work, Environment & Health. 16(6):394-400, 1990 Dec.
Authors Blair A. Saracci R. Stewart PA. Hayes RB. Shy C. Title Epidemiologic evidence on the relationship between formaldehyde exposure and cancer. [Review] Source Scandinavian Journal of Work, Environment & Health. 16(6):381-93, 1990 Dec.
Authors Blair A. Stewart PA. Hoover RN. Title Mortality from lung cancer among workers employed in formaldehyde industries. Source American Journal of Industrial Medicine. 17(6):683-99, 1990.
Authors Boysen M. Zadig E. Digernes V. Abeler V. Reith A. Title Nasal mucosa in workers exposed to formaldehyde: a pilot study. Source British Journal of Industrial Medicine. 47(2):116-21, 1990 Feb.
I hope these have what your colleague is looking for.
Leon
-- Leon A. Metlay, M.D.,Associate Professor of Pathology and Laboratory Medicine University of Rochester Medical Center Phone: (716) 275-5691 P.O. Box 626 Fax: (716) 273-1027 Rochester, NY 14642 lmetlay-at-acu.pathology.rochester.edu http://www.urmc.rochester.edu/smd/pathres/URPLM.html "Most ass drivers are evil, most camel drivers are decent, most sailors are saintly, the best among physicians is going to Gehenna, and the best of butchers is a partner of Amalek" -R. Judah, in Mish. Kidd. 4:14
Considering the current, and potential future state of Apple computers, I wonder how many people out there would be interested in a PC compatible interface for a Gatan PEELS. I am not trying to sell one, would like one myself; the target is that if a number of other people are interested in might be possible to push harder various companies to market such an interface.
} Hi All } For teaching purposes to show simple diffraction patterns and tilting } thereoff, as well as to demonstrate twinning we chose the old route of } preparing thin (20nm) gold crystal by by evaporating firstly Ag then Au } on air cleaved NaCl at 400 to 450 degrees C (10-5 torr). } We experience a few problems to get reproducible crystals: } 1. Sometimes the Ag surface turn whitish in stead of silver. } 2. The Ag does not completely dissolve in nitric acid (various } concentrations tried...). } } Can somebody help or refer me to literature on the subject or maybe } suggest other routes for simple preparation of such demonstrating foils? } } Thanks in advance } } Sara Prins } Surface and Structure Analytical Services } Division for Material Science and Technology } CSIR } PO Box 395 } Pretoria } 0001, South Africa } +27+12+8413974 } sprins-at-csir.co.za
Can't help with the gold, but I'd recommend molydenum oxide for similar uses, and it's a lot easier to prepare. Slowly heat a molybdenum strip or length of wire in air until a white smoke comes off. Wave a grid through the smoke. That's it - the grid is covered in molydenum oxide crystals, of various sizes, some twinned. Nice, easy single crystal diffraction patterns and you can use the specimen to calibrate the rotation relationship between the image and diffraction pattern.
Before I am completely swamped by emails, I am not talking about a sophisticated and expensive system that controls the microscope as well as the PEELS (i.e. the EMiSPEC system) but something a little more modest that only controls the PEELS, and does not cost $50K ! /
I too would be interested in knowing a simple way to distinguish among the common types of diffusion pump oils. One way to tell if you have a silicone oil might be to smear a bit of it on a metal stub and run an EDX spectrum of it to see if it contains Si (Maybe it would be better to burn some in a platinum or tungsten boat and examine the ash for Si). However, there is undoubtedly someone out there who will know a simpler method.
It is true that diffusion pumps will often perform at an acceptable level, even after thay have been savagely mistreated. However,after a diffusion pump has been run for any significant period of time without proper cooling water,or after exposure to air at high pressures, or after failure of the mechanical backing pump, the oil in it is likely to have been depleted, oxidized, and/or thermally degraded enough so that the pump no longer performs optimally, and is highly likely to exhibit an abnormally high level of backstreaming. (See 'Vacuum Methods in Electron Microscopy', p 214-220 for a detailed discussion.) The silicone and perfluorinated polyphenyl ether oils are the most resistant to such degradation, the polyphenyl ether oils are pretty good, while the synthetic ester and hydrocarbon fluids are much less so (p. 180-188). In any event, it is best to service a pump as soon as possible after such a potentially damaging event has occurred, just to minimize the liklihood that the vacuum system will become seriously contaminated with degraded pump oil.
Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:313-763-4788; Ph:313-764-3321
I wish to offer a correction and apology for my sin of omission.
In some comments I made over this Listserver a few days on methods for cleaning TEM specimen holders ago I stated that, "The latest method method for these holders is Plasma Discharge Cleaning, and Southbay Technologies markets a device that is specially designed for this purpose". Insofar as I know this statement is correct (except that the name should be 'Southbay Technology'); however, I have been reminded that the method was developed by Nestor Zaluzec and patented by Argonne Nat'l. Lab., and that two other companies also market Plasma Cleaning devices: namely, SPI Supplies and E. A. Fischione. This was an oversight on my part, caused in part by the fact that I was a bit loose in the wording of my comments, but also because I apparently don't keep very up-to-date on the latest developments in the marketplace for EM supplies (with my luck, two or three other companies are probably also in the buisness by now, and so I'll be off again).
In any event, I have no commercial interest in this matter, and was not trying to offer information prejudicially favoring any particular company over any other. I've been involved in the field of electron microscopy for so long that I have friends in most companies associated with the field, and so my intention is to remain as unbiased as possible. I'll try to be more careful henceforth.
Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:313-763-4788; Ph:313-764-3321
1) We would like to contact Beverly Giammara for some help and information regarding her publications on flat molds for embedding tissue using the microwave. If any one has any information on how to contact her we would greatly appreciate it.
2) To any one else doing microwave embedding
We are a lab that deals with muscle and nerve samples. We would like to use our new microwave to embed the tissue in resin (Spurr's or LR White). We tried Beem capsules but were unable to orient the tissue properly for sectioning with our MT2-B. I have seen reference made to the use of flats molds in the microwave and wonder if any one has any experience or suggestions they could share with us.
Thanks in advance
Christine Brantner and Susan Danielson Muscle/Nerve Lab Froedtert Hospital Milwaukee WI
We are interested in which lazer printers people have had experience using for routine biological EM images. Our images are captured with a Kodak Megaplus 1024x1024. We would also use the printer for LM, anatomical line drawings, AR of gells etc. We are considering the Lexmark Optra R+ 1200 dpi. Thanks for your help.
Rick L. Vaughn EM Research Facility Dept. Cell Biology & Anatomy Univ. Neb. Med. Ctr.
Hi everybody, And specially people working on asbestos. I would like to know which method is used in the other countries (USA UK Canada Germany....) to determine the concentration of asbestos in atmosphere. By method I mean when a laboratory receive a filter from a suspected place do they use a TEM or SEM for counting fibers and how? Do they use electron diffraction or EDS to determine the nature of asbestos? Thank you very much for the answers. ========================================================== Jacky Larnould tel 33 (0)4 67 72 28 26 fax 33 (0)4 67 79 54 90 email larnould-at-mnet.fr
Does anyone have any experience with SEM of reconstituted rat tail collagen matrix? The collagen is laid down onto glass coverslips and then cells are plated on top of the matrix. I am interested in the collagen more than the cells, but can't get any definition of fibers. In some areas there is some definition, but the majority of the surface seems compacted with little or no definition. I have tried a variety of preparation conditions including different fixatives as well as cpd vs. freon for drying. The latter seemed to produce the best results, but there is still little definition of the matrix. I have sputtered for different times, but I still seem to have a problem of charging that eventually burns the sample no matter what kV I use. Does this sound like a preparation problem, an imaging problem, or both? Any help would be greatly appreciated. Thanks. Bill Swaim
Hi, I am looking for any publications which contain micrographs of plant cell necrosis. I am specifically interested in sclerenchyma cells, but any papers on necrosis would be helpful. Thank you. Debby LeBlanc
} } We are interested in which lazer printers people have had experience } using for routine biological EM images. Our images are captured with a } Kodak Megaplus 1024x1024. We would also use the printer for LM, } anatomical line drawings, AR of gells etc. We are considering the } Lexmark Optra R+ 1200 dpi. Thanks for your help. } } Rick L. Vaughn } EM Research Facility } Dept. Cell Biology & Anatomy } Univ. Neb. Med. Ctr.
We use the Lexmark Optra RX printer in our lab for routine image printing and we are very happy with it. We are a materials lab here but I think you would be happy with it for your biological images as well.
Good Luck,
Margaret E. Bisher
NEC Research Institute 4 Independence Way Princeton, NJ 08540. Tel.: (609) 951-2629 Fax: (609) 951-2496 e-mail: peggy-at-research.nj.nec.com
I have a JEOL 840 SEM that was purchased in 1986, and we are considering putting it up for sale. I would like some feed back on what this instrument might be worth or what you a potential buyer would offer if interested.
The scope has both SE and BSE detectors, plus a PGT System III X-Ray detector. The scope is currently in operation and has been under service contract with Jeol for the last 5 years., Overall it is in excellent condition.
Please respond directly to me and not this list either by e-mail, phone or fax.
Thank you.
Joe Goodhouse Confocal / E.M. Core Facility Dept. of Molecular Biology Princeton University
It would seem to me that the simplest way of determining if silicone oil is in the diffusion pump (as opposed to something else?) is to take an Infrared scan - silicone oil has very distinctive absorption bands in the "fingerprint" region of about 1450 - 700 wavenumbers. Examples can be found in just about any IR reference book. One could also monitor the quality of the oil by taking an initial IR and periodically checking subsequent spectra against it.
Regards,
-Bob ********************************** Bob Citron Chiron Vision 555 W. Arrow Hwy Claremont, CA 91711 USA PH: (909)399-1311 Email: Bob_Citron-at-cc.chiron.com **********************************
We have been using a red new fuschin/alkaline phosphatase reaction to tag a cytoplasmic protein. It transmits light maximally at 600 nm, and fluoresces with a rhodamine cube.
We are looking for similar dual-function chromophores to label cytoplasmic proteins and nucleotides.
Susan Danielson writes: } 1) We would like to contact Beverly Giammara: Her email address is } {bgiammara-at-magnum.mco.edu}
} 2) To any one else doing microwave embedding: } We are a lab that deals with muscle and nerve samples. We would like to } use our new microwave to embed the tissue in resin (Spurr's or LR White). } We tried Beem capsules but were unable to orient the tissue properly for } sectioning with our MT2-B. I have seen reference made to the use of } flats molds in the microwave and wonder if any one has any experience or } suggestions they could share with us.
RESPONSE- There are two approaches in the literature for microwave accelerated curing of resins: 1) Giammara's approach for flat embedding molds and 2) Giberson and Demaree's approach for Beam Capsules.
My suggestion for flat embedding molds is to start with 50% power for 15 minutes (100% will definately give you disappointing results). Also when using flat embedding molds, allow your blocks to cool for 15 minutes before removing them from their molds, and vent your microwave oven during curing.
I highly recommend using an appropriately sized water load for your oven during microwave curing in flat embedding molds (otherwise there is simply too much energy in a microwave oven and specimen damage from over heating will result). In addition, microwave curing in an uncalibrated microwave oven is very tricky and usually results in disappointing results (e.g., incomplete curing of blocks). Simple tools that you can make and a detailed description of how to use them to CALIBRATE YOUR MICROWAVE OVEN are published in the The Microwave Tool Book.
When curing resins in BEEM capsules, they are placed IN a water bath- temperature never exceeds 100 =B0C and curing times are ~ 75 minutes. See the reference by Giberson RT, Demaree RS, Jr: Microwave fixation: understanding the variables to achieve rapid reproducible results. Microsc Res Tech 32:246, 1995
Detailed information regarding curing times of various resins in a microwave device can be found in: 1. Giammara B. Microwave embedment for light and electron microscopy using Epoxy resins, LR White, and other polymers. Scanning 1993;15:82-87.
2. Login GR, Dvorak AM. The Microwave Toolbook. A Practical Guide for Microscopists (Beth Israel Hospital, Boston, 1994). The book contains a table of curing times for resins tested.
Please contact me if you have additional questions and I will respond directly to you.
Dr. Gary R. Login Dept. Pathology Beth Israel Deaconess Medical Center 330 Brookline Avenue Boston, MA 02215
Susan Danielson writes: } 1) We would like to contact Beverly Giammara: Her email address is } {bgiammara-at-magnum.mco.edu}
} 2) To any one else doing microwave embedding: } We are a lab that deals with muscle and nerve samples. We would like to } use our new microwave to embed the tissue in resin (Spurr's or LR White). } We tried Beem capsules but were unable to orient the tissue properly for } sectioning with our MT2-B. I have seen reference made to the use of } flats molds in the microwave and wonder if any one has any experience or } suggestions they could share with us.
RESPONSE- There are two approaches in the literature for microwave accelerated curing of resins: 1) Giammara's approach for flat embedding molds and 2) Giberson and Demaree's approach for Beam Capsules.
My suggestion for flat embedding molds is to start with 50% power for 15 minutes (100% will definately give you disappointing results). Also when using flat embedding molds, allow your blocks to cool for 15 minutes before removing them from their molds, and vent your microwave oven during curing.
I highly recommend using an appropriately sized water load for your oven during microwave curing in flat embedding molds (otherwise there is simply too much energy in a microwave oven and specimen damage from over heating will result). In addition, microwave curing in an uncalibrated microwave oven is very tricky and usually results in disappointing results (e.g., incomplete curing of blocks). Simple tools that you can make and a detailed description of how to use them to CALIBRATE YOUR MICROWAVE OVEN are published in the The Microwave Tool Book.
When curing resins in BEEM capsules, they are placed IN a water bath- temperature never exceeds 100 =B0C and curing times are ~ 75 minutes. See the reference by Giberson RT, Demaree RS, Jr: Microwave fixation: understanding the variables to achieve rapid reproducible results. Microsc Res Tech 32:246, 1995
Detailed information regarding curing times of various resins in a microwave device can be found in: 1. Giammara B. Microwave embedment for light and electron microscopy using Epoxy resins, LR White, and other polymers. Scanning 1993;15:82-87.
2. Login GR, Dvorak AM. The Microwave Toolbook. A Practical Guide for Microscopists (Beth Israel Hospital, Boston, 1994). The book contains a table of curing times for resins tested.
Please contact me if you have additional questions and I will respond directly to you.
Dr. Gary R. Login Dept. Pathology Beth Israel Deaconess Medical Center 330 Brookline Avenue Boston, MA 02215
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We have an Hitachi SEM that uses threaded stubs. On the suggestion of Kevin Cronyn (Hitachi Sales) I bought plastic hinged-lid boxes (about 4" x9") from one of the EM suppliers and cut pieces of plexiglass to fit in the bottom. I then drilled and threaded 32 holes in the plexiglass and ran short (~1/2") bolts up through the holes. The thread size is the same as for the Hitachi stubs so you just screw the stubs down on the bolts and set the whole unit in the plastic box. I put one longer (~1") screw in the middle to act as a handle for getting the plexiglass out of the box. I seem to recall that it came to about $20 in supplies for each box as well as two hours of drilling and tapping a bunch of little holes. I can send more details if you are interested. For short-term student use I give them petri plates with double-sided tape in the bottom. Stubs are placed on the tape and stick pretty well. You can get up to 10 or so stubs in one standard Petri dish.
YWIA
Bob
Robert R. Wise Plant Physiologist and Director, UWO Electron Microscope Facility Department of Biology University of Wisconsin Oshkosh Oshkosh, WI 54901 (414) 424-3404 tel (414) 424-1101 fax wise-at-uwosh.edu
Can anyone out there direct me towards a decent monte carlo electron- specimin interaction modeling program? I'm looking for electron path, BSE energy and directional information. Provided that the code is in either fortran or C++ (or basic, I guess), I will be able to make minor modifications if the program(s) are not precisely suited to these uses. thanks, Ben Simkin (simkin-at-egr.msu.edu)
Dear Christine and Susan, and fellow microscopists,
A good introduction to Beverly Giammara's work with microwave embedding can be found in Chapter 23 of The Microwave Cookbook for Microscopists, by Kok and Boon, entitled "Microwave Exposure and Epoxy-resin Embedding for EM." This book is available through Energy Beam Sciences.
We also have a bibliography of papers relating to this subject at our World Wide Web site (http://www.ebsciences.com).
Using the method developed by Giammara, Spurr or LR White resin polymerization can be done in about 30 minutes in a laboratory microwave.
Best regards, Steven E. Slap, Vice-President ******************************** Energy Beam Sciences, Inc. Adding Brilliance To Your Vision ebs-at-ebsciences.com http://www.ebsciences.com/ ********************************
} What is the best way to store SEM samples (those already on stubs and } sputter coated)? } Best way we have found is to use storage boxes provided by SPI, EMS or Pella (clear plastic boxes) and place in either a glass desiccator or zip-lock bag with desiccant. The boxes offer the advantages: numerically labeled for specimen ID, hold the specimens tightly so that they will not spill out if inverted or tipped.
A cheaper alternative is to take some 1/2" plexiglass and drill a series of holes that will allow the stubs to fit. A dab of sticky tab will adhere the stub to the plexiglass. If one attaches small legs, the plexiglass panels may be stacked on top of each other. This may then be desiccated.
Cheapest yet, someone (EMS or Pella or SPI) makes some paper boxes (like "pill boxes" of olden days) that you can write on.
Good luck.
#################################################################### John J. Bozzola, Ph.D., Director Center for Electron Microscopy Southern Illinois University Carbondale, IL 62901-4402 U.S.A. Phone: 618-453-3730 Fax: 618-453-2665 Email: bozzola-at-siu.edu Web: http://www.siu.edu/departments/shops/cem.html ####################################################################
Dear Ben, The program Electron Flight Simulator will do all that and some other neat things besides. You will find references in any Microscopy Today or the Exhibitors Bulletin of the last MSA meeting and there is a Web site. It costs about $480 and runs on a PC. Other than that, David Joy is the writer of most of those programs, and should be able to help you with a free version. You wrote: } Can anyone out there direct me towards a decent monte carlo electron- } specimin interaction modeling program? I'm looking for electron path, } BSE energy and directional information. Provided that the code is in either } fortran or C++ (or basic, I guess), I will be able to make minor modifications } if the program(s) are not precisely suited to these uses. } thanks, } Ben Simkin (simkin-at-egr.msu.edu) } Regards, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
Here at the museum our SEM samples are frequently from registered specimens from the collections and are often the type specimens of new species. Our stubs are, therefore, stored "in perpetuity" like the rest of the collections. Years ago I asked some questions regarding conditions for permanent storage but there wasn't much info forthcoming apart from the usual methods. For what it's worth, here are some of my observations on stubs 15-20 years old.
The oldest stubs in our museum have been stored in large (~300mm diam.) glass petri dishes, stuck down on double-sided sticky tape. These petri dishes are kept in stacks of three in glass dessicators (with silica gel) which are sealed with petroleum jelly. Most of them are still good for the SEM - the bad ones are attributable to poor preparation (and subsequent degradation) rather than storage conditions. Others have used disposable plastic 110mm dishes, however, this is not so space-efficient.
I guess that low humidity and constant temperature are the important factors. I've thought (comments please) that it might be worth replacing the air with an inert gas as well.
We then looked at perspex cabinets with shelves. None were to our liking (usually too few shelves and too expensive) so we designed our own for a person who wanted to produce them for his supply shop.
Originally we had planned for a stackable perspex cabinet (340mm wide, 280mm deep, 260mm high) with O-ring in the door, full-length side hinge, roller clips to provide pressure on the O-ring, gas exchange taps (pump inert gas in through one and air out the other) and 10 shelves which held 1,760 stubs. Unfortunately, supply of parts and costs for materials and labour, on what was only ever going to be a small run, meant considerable changes and the result can only be called a very efficient dust cabinet (still stores 1,760 stubs!). With monthly changes of silica gel it works as a dessicator.
Any supply houses interested in bringing this design to fruition?
Geoff Avern Microscopy Laboratories Australian Museum Sydney, Australia
P.S. Paula, please say hello to Carole Hickman (Palaeontology) if you see her.
I am presently reassessing the anti-corrosion/anti-microbial growth additive to use in our two EM cooling systems. The questions that I am having difficulty in finding answers to are;
1)What are the properties of water that cause corrosion in the electron microscope? Is it the pH, water contents or both?
2)What is the best pH for EM cooling systems?
3)Has anybody used the Coalite Chemicals product 'Phylatol' in their EM cooling systems?
Thanks in advance.
Allan Mitchell
Please send replies to: allan.mitchell-at-stonebow.otago.ac.nz
Does anyone know of any critiques comparing/contrasting the various commercial & shareware packages for microscopy such as Metamorph, Metafluor, NIH Image, Axon Image Workshop, Global Image, Image Tools (Un. of Texas), etc.?
Is this the appropriate forum for such a comparision, or does it exist elsewhere? Thanks, Sandy Simon
Sanford M. Simon Laboratory of Cellular Biophysics Box 304 Rockefeller University 1230 York Avenue New York, N.Y. 10021 (212) 327-8130 (voice) (212) 327-8022 (fax) simon-at-rockvax.rockefeller.edu (e-mail)
"Well I ain't often right, but I've never been wrong It seldom turns out the way it does in the song, Once in awhile you can get shown the light in the strangest of places if you look at it right..."
} What is the best way to store SEM samples (those already on stubs and } sputter coated)?
My first thought was "In peanut butter jars with dessicant, of course!" because that's what I just told my new SEM class and what I tell everyone else. Our main concern here in Hawaii is humidity, and I insist that all samples be held over dessicant for some time before going into our field emission SEM. Most of us put our pin-style stubs in commercially available boxes and find that, once sputter coated, they will then store *indefinitely* over dissicant. The identification and procurement of suitable jars is a serious subject here, especially now that many brands of peanut butter are now available only in plastic jars with a thin, styrofoam-like seal, driving us to other snacks that come in jars with the requisite rubber ring in the lid. Jellies and pickles and other fluid items frequently come in jars with wide mouths, allowing room for insertion of fingers to retrieve sample storage boxes. Mayonnaise jars, alas, do not have the rubber ring in the lid. Canning jars are popular among our customers with active grants to pay for them. Be warned, however, against using jars which may have strong residual scents; kim chee jars are a no-no. Avoid, too, jars which have contained spaghetti sauce or other tomato-based products as some strange mungy stuff likes to grow in them even after being subjected to multiple runs in the dishwasher. I have not attempted to autoclave them.
Tupperware brand storage boxes work well for a fair period of time; other brands do not seal well enough to keep indicator dessicant from indicating. My Tupperware lady thinks I'm nuts. She may be right.
Jars of all shapes and sizes full of stub boxes pile up in our facility until I run down their long-lost owners or shove them in their campus mail boxes. I can't help you with that problem!
If the question is, rather, how does one keep the stubs upright and undamaged if they are the type that does not fit snugly in comercially available storage boxes, or one can't afford said boxes, I am of less help. I like to encourage my customers and students to be creative (I have an interesting collection of boxes designed to hold glass knives, for example). I have not yet tried to see if 1/8" pin-type stubs fit in the holes of pipettor tip boxes. Hitachi screw-on stubs are such a pain that I made an adaptor to hold pin-type stubs before I took delivery of the 'scope. I remember that you have an ISI DS-130, but I don't remember the stub type.
Last week I looked at some stubs of unknown origin that had been knocking around in a petri dish in a desk drawer for at *least* 12 years. I put them over silica gel for a day and popped them into the 'scope without further coating and found some wonderful cultured cells that looked just great!
I'd rather be in the lab than home with this cold. (It's raining in Hawaii.)
Tina
MicroAngelo soon admitting gender and changing to MicroAngela http://www.pbrc.hawaii.edu/bemf/microangelo **************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
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What is the best way to store SEM samples (those already on stubs and sputter coated)?
We have chosen the expensive way by storing the samples in a vacuum cabinet. The vacuum is not very good (rough pumping) but sufficient to prevent damages of the sputtered layer, water vapor uptake and/or oxidation of the samples. As our (Philips) stubs have a pin underneath, we have drilled holes in the cabinet's shelves. This way the samples are fairly secured when you move the shelves. This storage is meant for samples we might want/need to put back in the microscope. Once they are no longer current, we have a large drawer with a rubber foam (neoprene) layer in which we've drilled holes too so that the pin stubs will fit. It works very well and if you reference your shelves and drawers, you might even be able to actually find old samples back: -).
Have a nice day
J.-M. Boichat e-mail: jean-marc.boechat-at-chma.mhs.ciba.com EM LABS Ciba Research Center phone:++41264356979 fax:++41264356907 P.O. Box 64 1723 Marly 1 Switzerland Disclaimer: Nobody in this company ever mind what I say why would they start now!
Message-Id: {1.5.4.32.19970122140553.006bd218-at-biotech.ufl.edu} X-Sender: gwe-at-biotech.ufl.edu X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"
For short term storage we have used several of the methods already described, depending on the state of our budget at the time. For extended storage of samples that you really don't expect to ever look at again but someone insists that you archive, we have taken to using the commercial storage box placed in a seal-a-meal bag with some charged silica gel. The bag is evacuated and sealed for storage on a high shelf in the lab. The indicator in the silica gel shows that it is still dry after three years. ******************************************************* G.W. Erdos, Ph.D. Phone: 352-392-1295 Scientific Director, ICBR Electron Microscopy Core Lab 218 Carr Hall Fax: 352-846-0251 University of Florida E-mail: gwe-at-biotech.ufl.edu Gainesville, FL 32611 http://www.biotech.ufl.edu/~emcl/ Home of the #1 Gators ***** "Many shall run to and fro, and knowledge shall be increased" Daniel 12:4
------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America
What is the best way to store SEM samples (those already on stubs and sputter coated)?
We have chosen the expensive way by storing the samples in a vacuum cabinet.
The vacuum is not very good (rough pumping) but sufficient to prevent damages of the sputtered layer, water vapor uptake and/or oxidation of the samples.
As our (Philips) stubs have a pin underneath, we have drilled holes in the cabinet's shelves. This way the samples are fairly secured when you move the shelves. This storage is meant for samples we might want/need to put back in the microscope. Once they are no longer current, we have a large drawer with a rubber foam (neoprene) layer in which we've drilled holes too so that the pin stubs will fit. It works very well and if you reference your shelves and drawers, you might even be able to actually find old samples back: -).
------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America
To: Microscopy ListSer {Microscopy-at-MSA.Microscopy.Com}
Yes, we're interested in SW for image capture process and print. Please include image capture cards.
Right now, we're hung up with micro-channel bus computers and old IBM Video Capture Adapter cards. The greatly restricts the choices. We use Perfect Image/2 to capture, but we have to save the images and open them with Paint Shop Pro in order to anotate and print them. Our Lexmark Optra 4049 gives us nice 1200 dpi prints on plain paper. This system is complicated to use, but works. We may try to get ISA bus machines and new capture cards if it looks worthwhile.
Please tell us where there might be comparisons of cards and sw packages for SEM and light optics image work. TIA,
} We are interested in which lazer printers people have had experience } using for routine biological EM images. Our images are captured with a } Kodak Megaplus 1024x1024. We would also use the printer for LM, } anatomical line drawings, AR of gells etc. We are considering the } Lexmark Optra R+ 1200 dpi. Thanks for your help. } } Rick L. Vaughn } EM Research Facility } Dept. Cell Biology & Anatomy } Univ. Neb. Med. Ctr.
Hi Rick and Everyone, We have used the Lexmark Optra R printer in our lab for routine image printing for about 1 1/2 years and we WERE very happy with it. Recently, the high voltage regulator broke down and cooked a couple of toner cartridges. After talking to my refiller guy (been very knowledgable for years), it seems there is a longevity problem with these printers!! Several of his Lexmark clients have have opted (no pun intended) for another brand of printer. At this point he swears at them rather than by them. But, this is one man's opinion, and before I condem them completely, I would like to know if anyone else (or how many) has experienced this.
Cheers :) George Department of Earth and Atmospheric Sciences University of Alberta Edmonton, Alberta T6G 2E3 Canada ph: 403-492-5746 fax: 403-492-2030
We are beginning a series of experiments that will include labeling of = adipocytes for light microscopy, followed up by electron microscopy. = Preliminary experiments show that adipocytes are very autofluorescent, so = I was wondering if it is better to do immunoperoxidase staining when = working with these cells. If anyone is familiar with working with = adipocytes, and can give me any advice on which way is best to label = these cells, or if one block was found to be superior over another, I = would appreciate the information very much.
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To: Microscopy ListSer {Microscopy-at-MSA.Microscopy.Com}
I've got a set of these models on my FTP site, and everyone is welcome to them. I worked with Dave Joy in the mid '80's to convert these from Apple basic to IBM Basic. Later I took them from CGA to VGA resolution. They're compiled Quick Basic. The source code is not included, since I'm concerned about someone changing the code and effecting the validity of the results.
We have a Lexmark Optra Lxi well. It is installed on the network. I don't know how many people use it, but about a year ago, it was plugged in and turned on. The only maintenance I know has been to fill it with consumables.
------------------------------------------------- Harold J. Crossman OSRAM SYLVANIA INC. Lighting Research Center 71 Cherry Hill Dr. Beverly, MA 01915 Phone: (508) 750-1717 E-mail: crossman-at-osi.sylvania.com
Our web sites: www.sylvania.com www.siemens.com --
We have a Lexmark Optra Lxi well. It is installed on the network. I don't know how many people use it, but about a year ago, it was plugged in and turned on. The only maintenance I know has been to fill it with consumables.
------------------------------------------------- Harold J. Crossman OSRAM SYLVANIA INC. Lighting Research Center 71 Cherry Hill Dr. Beverly, MA 01915 Phone: (508) 750-1717 E-mail: crossman-at-osi.sylvania.com
Our web sites: www.sylvania.com www.siemens.com --
Hi, I need to count virus particles/ml of several viral suspensions with the viruses ranging in size from 20nm - 100nm. I need something quick and easy to give me a rough idea of the numbers. I've found some general information using polystyrene latex particles to do this, but I'd like to get a detailed protocol if anyone has one. 1. Do I need to get different sized latex particles for each virus size? The smallest latex I've found so far is 85nm. 2. Does anyone have a source for the latex? The companies I've called use them for mag. calibration and couldn't tell me how many particles/ml they contained. 3. Can I spray my sample on my grid with a nebulizer or should I drop it on? If I can spray it on, will I alter my count because of the extra water and PTA I'll be using?
Thanks for your help. Debbie Cassout TVMDL e-mail : dcassout-at-tamu.edu fax: (409) 862-7047
Can somebody please explain what Charge Contrast Microscopy is? I found this technique mentioned in a paper related to the analysis of ceramics, using a FEG-SEM. I was not successful in finding a description of this technique in my standard textbooks on microscopy or any of the microscopy related web-sites. Thanks for the help,
Hi Everyone, I am interested in attending an ultra microtoming class and I need information about a date, place and cost of an upcomming class if there is one. I work in the materials area, not biological. Thank you very much in advance, Jane Glamp glamp-at-ppg.com
Our larger o-rings usually come packaged with each o-ring having two or more overlapped turns. One of these o-rings must be inserted in a groove on the bottom of a plate in the scope, and I have not found a way to unfold the o-ring into a circle which will lay flat. I have put a book on it overnight and put it around a beaker slightly larger than the ID, but neither of those is satisfactory. I don't want to deform the o-ring, so I haven't been too rough with it. I am trying the beaker again, this time filled with hot water. (If the cold caused the o-ring on Challanger to harden, maybe the hot water will soften one.) Other than using so much grease that it holds the o-ring in place--obviously not good practise--I haven't found a way to keep the deformed o-ring in place. Has anyone out there solved this problem? TIA. Yours, Bill Tivol
Several people have asked me to post the replies I've received to my recent call for help...how to stain agar for acrylic resin embedding? I'm not going to post the complete replies - just a summary (lazy today). SO: *Fast green when the tissue is in 100% EtOH. Add a few ul of a 7% fast green solution to the vial with the samples. Doesn't work well with acetone. *Alizarin red for acetone dehydrations. *A light coat of india ink on the outsides of the agar blocks. *Dilute eosin (nobody ever says how dilute!). Acidified eosin. 1% Eosin B. *Alcian Blue. *2% Safranin O in the 100% EtOH step. *Mix some Dextran Blue in the agar.
There were also suggestions to fix with osmium or picric acid...both will color the material. Won't work for my samples, but...something to keep in mind.
Thanks to everyone who responded - I'm going to give the fast green a whirl today, since I have some on hand.
If anyone wants more info, I have the original messages and can hook you up with the people who sent them.
Hi Everyone, I am interested in attending an ultra microtoming class and I need information about a date, place and cost of an upcomming class if there is one. I work in the materials area, not biological. Thank you very much in advance, Jane Glamp glamp-at-ppg.com
You've probably heard from every vendor and his or her dog by now, and we also sell a variety of SEM specimen storage boxes, but, in my opinion, the *best* storage method is a good desiccator cabinet with shelving having holes to accomodate the specific specimen mounts you are using. At least two of the EM supply companies sell such systems, Energy Beam Sciences being one of them. My second choice, for standard "pin-type" specimen mounts, would be this lovely wooden mount storage box, made in the U.K., and sold by at least the same two vendors.
Best regards, Steven E. Slap, Vice-President ******************************** Energy Beam Sciences, Inc. Adding Brilliance To Your Vision ebs-at-ebsciences.com http://www.ebsciences.com/ ********************************
I have heard that organic diffusion pump oils could ignite under certain conditions. Can anyone confirm this or has anyone heard of such an event happening?
Ciao for now, Ken
Kenneth JT Livi Department of Earth and Planetary Sciences 34th and Charles Streets The Johns Hopkins University Baltimore, Maryland 21218
I count regurlarly virus particles with latex beads. You can use latex beads at a size between 90-140 nm at a concentration of about 10^8 beads/mL. You can find this beads with a known concentration at Marivac ltd, Halifax, Nova Scotia. (tl.902-429-0209). My protocol consist to mix 100 uL of viral suspension with 100 uL of latex beads in a 240 uL "Beckman Airfuge" tube. Place a grid in the bottom of tube. Centrifugate at 20 psi (about 120 000g) during 5 min. Take the grid, dry it and stain with phosphotungstic acid (PTA 3%, pH 6). I count on 2 differents grids at least 200 virus or beads in different areas.
Viral particle concentration (part/mL)= virus count / latex beads count X latex bead conc. X 1/dilution of test article
You can find my Airfuge technique in:
Alain R. and al., J.Vir.Methods, 16 (1987): 209-216
I don't have experience with nebulizer but I think it's a good conpromise.
Don't hesitate to write me if you want more details.
Robert Alain Microscopie Electronique Institut Armand-Frappier Laval, Quebec
Robert_alain-at-iaf.uquebec.ca
Hi, I need to count virus particles/ml of several viral suspensions with the viruses ranging in size from 20nm - 100nm. I need something quick and easy to give me a rough idea of the numbers. I've found some general information using polystyrene latex particles to do this, but I'd like to get a detailed protocol if anyone has one. 1. Do I need to get different sized latex particles for each virus size? The smallest latex I've found so far is 85nm. 2. Does anyone have a source for the latex? The companies I've called use them for mag. calibration and couldn't tell me how many particles/ml they contained. 3. Can I spray my sample on my grid with a nebulizer or should I drop it on? If I can spray it on, will I alter my count because of the extra water and PTA I'll be using?
Thanks for your help. Debbie Cassout TVMDL e-mail : dcassout-at-tamu.edu fax: (409) 862-7047
} Can somebody please explain what Charge Contrast Microscopy is? I found } this technique mentioned in a paper related to the analysis of ceramics, } using a FEG-SEM. I was not successful in finding a description of this } technique in my standard textbooks on microscopy or any of the } microscopy related web-sites. Thanks for the help, } } Hasso Weiland } } Alcoa Technical Center } Alcoa Center, PA 15068
Not a term I have come across. My first thought was EBIC - electron beam induced current - one step on from specimen current imaging, but both of these only apply to conductors or semiconductors.
As the specimen is an insulator, I guess the term is being used synonymously with voltage contrast. Again, mainly used for semiconductors but has been applied to ceramics. Non-conducting, or poorly conducting specimens charge if not coated. If everything is balanced out correctly, you can achieve a steady state where the charge input to the specimen equals the charge leakage to ground. Sometimes a very thin carbon coat, as used for EDX, is applied to help establish steady state conditions. In some specimens this is useful and contrast in images relates via the level of charge in different parts of the specimen to, among other things, local conductivity. Not very quantitative but quite sensitive. Check Goldstein et al (1992), Scanning Electron Microscopy and X-ray Microanalysis, 2nd Edition, Plenum Press, pp 557-562.
Regards,
--------------------------------------------------------------- Dr L. P. Stoter Technical Editor, MICROSCOPY & ANALYSIS Technesis 17, Rocks Park Road email: LPS-at-teknesis.demon.co.uk Uckfield, E. Sussex Phone: +44 (0)1825 766911 TN22 2AT Fax: +44 (0)1825 766911 United Kingdom ---------------------------------------------------------------
This is great! Ask and you shall recieve. In regards to George Braybrooks and Scott Whittaker's comments this makes two strikes against Lexmark. I didn't mention in my original message regarding lazer printers that we had tried several years ago using Lazer Master's card to double a HP4's resolution, but it took 50% of the RAM upon loading and was finicky with some hardware. Those of you that mentioned other cards: how are they for RAM usage and cost. Not to put down SEM but they seem to get by with non-photo printing easier than us with TEMs. An SEM print off our HP4 looks much better than the TEM?
I've taken on the responsibility of assembling separate short course and future meeting listings for the revamped journal of MSA, MAS and MSC: "Microscopy and Microanalysis," which will go to over 5,000 scientists.
If you have, or know of anyone who has, information concerning future short courses and/or topical meetings of interest to microscopists internationally, please send e-mail directly to me (not the listserver).
We will publish in date order short paragraphs giving Date and Title of the short course or meeting; Location; Name, phone, mail and e-mail ad- dresses of a contact person(s); and a short (50 word) description of the event.
The Jan/Feb issue is at press. The Mar/Apr issue closes this Friday, 24 January. If you wish to be listed in this issue e-mail (ascii format) me *TODAY* and I'll try my best to fit your contribution in.
Send me a e-mail for closing dates for the balance of the issues for 1997.
---------- } From: Jacky Larnould {larnould-at-mnet.fr} } To: Microscopy-at-Sparc5.Microscopy.Com } Subject: Asbestos counting } Date: Tuesday, January 21, 1997 1:35 PM } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } Hi everybody, } And specially people working on asbestos. } I would like to know which method is used in the other countries (USA UK } Canada Germany....) to determine the concentration } of asbestos in atmosphere. } } Jacky Larnould } tel 33 (0)4 67 72 28 26 } fax 33 (0)4 67 79 54 90 } email larnould-at-mnet.fr } The following meyhods are currently in use for measuring airborne asbestos concentrations. 1. Phase contrast microscopy (PCM): U.S. and Britain for most occupational exposures 2. SEM: Germany, all exposure measurements 3. TEM: U.S. testing for airborne concentrations after asbestos removal operations in schools, for certain occupational studies and some public buildings.
PCM really gives total airborne fiber concentration because asbestos cannot be differentiated from any other fiber of similar size. SEM methods rely on EDS for identification but cannot differentiate asbestos from other mineral fibers with the same chemical composition but different crystalline structure. TEM uses both EDS and SAED and is the only method currently acceptable in law courts in the U.S.
The individual protocols for each are too involved to post on this server. If you are interested, contact me by email strangedoc-at-fuse.net and I'll try and help you further. K. A. Brackett, Ph.D.
From Microscopy-request-at-Sparc5.Microscopy.Com Tue Jan 21 18:45:42 1997 Mime-Version: 1.0
I received a lot of replying for my post on problem in zip disk. Many people said they have simlar problem. Finaly, I got my data recovered by Norton utility. It took very long time waiting the Norton to recognize the zip drive (it was keeping spin and click for 10+ minuts) and after recovering the files, the zip drive was completely damaged - any good-new disk will bdcame bad after insert to the drive. I called iomega then and got a return number to repair the drive. I'd like thank all of you who responded my question.
**************************** * Maoxu Qian, Ph.D. * * Dept of MSE, box 352120 * * University of Washington * * mxq-at-u.washington.edu * * (206)543-1514(phone) * * (206)543-3100(fax) * ****************************
} Hi, Nestor. Your ideas on plasma cleaning for specimens and stages are most } welcome -- good for you! The next question is .... can the cleaning be done } in an EM without damaging an EDX window (a thin one)? --------- stuff cut out ---------- } Cheers, } Brian } ==============
Brian etal....
I guess I'm not sure what you want to really do here. Do you want to just clean the EDS window, or if I'm guessing correctly the interior of the column? If it's the column then this is a good concept! Obviously once you clean the stage the next area to consider is the immediate surroundings which are also sources of contamination. Assuming of course your not in the situation where the vacuum system itself is poor and overwhelming the whole process aka vintage 70's microscopes. On the other hand, if we are talking about only cleaning EDS windows I would not recommend this be done with plasmas as the cleaning time will be far too long. Assuming we are talking about cleaning a column, then my comments below apply.
Basically, what you have to remember is that the plasma is acting like a catalyst for a localized (surface) chemical reaction. The energy of the plasma is breaking weak bonds of the hydrocarbon compounds on the surface which then make the species somewhat volatile so that they can further react with the gas in the plasma. The subsequent action of the gas is to provide an additional chemical process which is converting the compound into a gaseous phase which can be easily removed by the mild vacuum conditions. For example here are some reactions which could be used if we were dealing only with pure carbon...
C + 2H2 -} CH4 ; C + CO2 -} 2CO; C + O2 -} 2CO .....
Lots of other possibilities exist depending on the materials and "gas". If the EDS window compound is a strongly linked polymer then you will need a high energy plasma to disassociate the OH bonds to make an appropriate reaction proceed. This will occur only if you are running plasma's on the order of 50eV, or with very chemically reactive gas compounds (i.e. something more than just Ar, O2 ....). In this regime you can easily "etch" polymers and thus also a hydrocarbon based EDS window. If on the other hand you run with only very low energy plasmas ( { 10 eV) this should not be a problem. I would recommend you test the EDS window material first, as in most materials, some compounds are more resistant than others. If you can't do it locally just send some to me and I'll try it here for you in some of my gobs of spare time! ;-) My best guess is that there will be a readily set of conditions which will not cause problems for most hydrocarbon based thin-window detectors, however I have yet to test any here at ANL. The other obvious advantage is that the plasma is nearly a RT process. I've measured temperature rises in a thermocoupled TEM stage of ~ 5 degrees C under cleaning conditions, which is less than one gets using a 150W flood lamp!
If you decide to try this yourself, then I would recommend that you use a 2 step process first pure Ar then O2. The Ar disassociates the most volatile compounds first which then get swept away pretty quickly. The O2 finishes the job on the stuff that is more strongly bound. The presence of O-rings in the column will not be a problem, since the sealing surfaces are protected from the plasma. As an example consider the o-rings on specimen stages which survive multiple treatments in a stand alone table top system without problems.
Hope that this answers your question.
Nestor
BTW, to keep everything on the up and up, I will remind you all that the use of reactive gas plasma for cleaning the interior of an electron-optical column ( SEM, TEM, AEM...) is covered by an patent owned by ANL, who is my employer.
Dear Hasso, I have never heard that term, but last year I was looking at sintered mixtures of SiC and Al2O3. The SiC was dark, because it is conductive and the Al2O3 was white, as it was charging. This only worked if the mixture was more than about 20% SiC, otherwise the Al2O3 charged so much it disrupted the picture. In order to try to keep the charging down I tried doing very short gold-palladium sputter coats of 20 seconds or less, but even 10 seconds of coating completely obscured this contrast. The technique would only work with a well-dispersed mixture of conductive and non-conductive material. The proportion is easily determined by area percent image analysis. You wrote: } Can somebody please explain what Charge Contrast Microscopy is? I found } this technique mentioned in a paper related to the analysis of ceramics, } using a FEG-SEM. I was not successful in finding a description of this } technique in my standard textbooks on microscopy or any of the } microscopy related web-sites. Thanks for the help, } } Hasso Weiland } } Alcoa Technical Center } Alcoa Center, PA 15068
Regards, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
Dear Bill, When our EM sevice engineer wants to "plump up" an o-ring that has been in service for a long time, he puts it into an oven at 50 degrees C for an hour. This seem to relax them and plump them back to round. Perhaps if you put them in an oven with a weight on them for a while, then keep a weight on them as you cool them down, this would flatten them enough. You wrote: } Our larger o-rings usually come packaged with each o-ring having } two or more overlapped turns. One of these o-rings must be inserted in a } groove on the bottom of a plate in the scope, and I have not found a way } to unfold the o-ring into a circle which will lay flat. I have put a book } on it overnight and put it around a beaker slightly larger than the ID, but } neither of those is satisfactory. I don't want to deform the o-ring, so I } haven't been too rough with it. I am trying the beaker again, this time } filled with hot water. (If the cold caused the o-ring on Challanger to } harden, maybe the hot water will soften one.) Other than using so much } grease that it holds the o-ring in place--obviously not good practise--I } haven't found a way to keep the deformed o-ring in place. Has anyone out } there solved this problem? TIA. } Yours, } Bill Tivol } Regards, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
I'm doing an ALCHEMI (Atom Location by Channelling Enhanced MIcroscopy) study on a dopant in cubic zirconia. The literary references I've found to date mostly deal with intermetallics where atoms A and B (and impurity atom X) *can* lie on either the alpha or beta site of a structure (e.g., L1o superstructure).
My problem: I'd like to find a reference or two on an ALCHEMI study of an ionic material where atoms A and B can *not* reside on either of the sites (meaning, for example, that Zr would not be found on the O sites and vice versa). The mathematical treatments in the above references allow for this to occur and often times rely on an iterative convergence to the site occupancies of the X atom.
If you are aware of specific ALCHEMI studies on ionic (and perhaps covalent) materials, I'd appreciate the reference.
} Our larger o-rings usually come packaged with each o-ring having } two or more overlapped turns. One of these o-rings must be inserted in a } groove on the bottom of a plate in the scope, and I have not found a way } to unfold the o-ring into a circle which will lay flat. I have put a book } on it overnight and put it around a beaker slightly larger than the ID, but } neither of those is satisfactory. I don't want to deform the o-ring, so I } haven't been too rough with it. I am trying the beaker again, this time } filled with hot water. (If the cold caused the o-ring on Challanger to } harden, maybe the hot water will soften one.) Other than using so much } grease that it holds the o-ring in place--obviously not good practise--I } haven't found a way to keep the deformed o-ring in place. Has anyone out } there solved this problem? TIA. } Yours, } Bill Tivol
Bill,
Not a problem I've faced, but how about putting it around the beaker, as you've been doing and then putting it in the deep freeze over night. When it comes out nice and hard, you'll probably have a minute or so to get it into place and the bottom plate located, wait a few minutes for it to soften and then tighten the bolts. Worth a try? ... :)
I can confirm that heat for restoring o-rings does work in many instances. For many years I have successfully used hot water to do this rather than an oven.
Regards
Robin Cross EM Unit, Rhodes University, Grahamstown, South Africa
Robin H Cross Director : EM Unit, Rhodes University, Grahamstown, South Africa eurc-at-giraffe.ru.ac.za - tel: +27 461 318168 - fax: +27 461 24377
Matthew Stough wrote: } I'd like to find a reference or two on an ALCHEMI } study of an ionic material where atoms A and B } can *not* reside on either of the sites (meaning, } for example, that Zr would not be found on the O } sites and vice versa). } .... } If you are aware of specific ALCHEMI studies on } ionic (and perhaps covalent) materials, I'd appreciate } the reference.
Dear Matthew, Much of the early work on ALCHEMI by Spence and Taftoe was done on ionic materials, e.g. with spinel structure. You will find several references in
J.C.H. Spence & J. Taftoe, Journal of Microscopy, vol. 130, pt. 2, May 1983, p. 147 - 154.
The papers by Rossouw et al. on axial channeling ALCHEMI are also concerned with ionic materials of spinel and perovskite structures:
C.J. Rossouw, P.S. Turner & T.J. White, Philos. Mag. B vol. 57, 1988, p. 209 - 225.
C.J. Rossouw, P.S. Turner, T.J. White & A.J. O'Connor, Philos. Mag. Letters 60, 1989, p. 225 - 232.
Personally, I have had good experience with the axial channeling method.
Best wishes, Jorgen.
-at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at--at- J. B. Bilde-Soerensen Materials Research Department Risoe National Laboratory DK-4000 Roskilde Denmark
} I guess that low humidity and constant temperature are the important } factors. I've thought (comments please) that it might be worth } replacing the air with an inert gas as well. } } Geoff Avern
Now that I've got email working again, I'll stick in my $0.02 worth. I agree with Geoff (and several others): humidty is very important. However, I'd rate protection against mechanical shock 2nd, then temperature, etc. Make sure the stubs are firmly mounted, sticky tape is only for temporary storage or for when you can be assured that specimens won't be moved. I've used specimens that I've shipped in a VW bug across country and ones shipped from Antarctica, and sticky tape would *not* have done the job. Stubs firmly mounted in commercial or specially made stub holders do OK. Also, make sure the specimens are firmly mounted on the stub--it can take only a small jar to knock specimens off the stub or de-orient them. Given the rough handling of specimens by many people, long-distance shipping isn't needed to lose samples, just a trip across the lab or campus. For medium to long term storage, vacuum (10-3) or *dry, oil-free* inert gas (N2 or Ar) is good; for archival storage, I'd exchange the air with N2 or Ar and then pump down. O2 can be a long term problem, but I wonder more about the general crud in the lab air. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
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To: Microscopy ListSer {Microscopy-at-MSA.Microscopy.Com}
If you have a bulk N2 system as we do, gas boiled off the liquid is super clean. We're plumbed up to it for air tables, sample blow off, and we bleed it slowly into those big plastic boxes with the foam door seals, bolted to the wall. This is convenient, ultra-dry, and close enough to vibration free. We just use any sample box designed for 1/8" stud sample mounts.
I was following the a discussion in the Confocal archives around 3/95 = regarding deconvolution of images. It was said at one point that to = accurately deconvolve an image, the complete system must be known. = Given a simple transmitted light microscope system, ie objective, = coverslip, etc, does anyone know what exactly must be "known", how one = goes about getting that information, and is there software that can take = that information to deblur or deconvolve an image? Also, can it be done = to a digitized image?
Gatan offers the following short courses at $750 each. Tim Hughan Gatan, Inc.
Gatan's 1997 Schools for Electron Microscopy:
Digital Microscopy April 7-10, 1997
EELS Imaging & Analysis April 15-18, 1997
Specimen Preparation April 28-30, 1997
Digital Microscopy
This course introduces TEM, STEM, and SEM users to the capabilities of Digital Microscopy. On-line digital imaging facilitates the immediate viewing of samples and has made quantitative acquisition and analysis of electron micrographs and diffraction patterns possible. The course will explore the parameters necessary to optimize TEM, STEM, and SEM image acquisition, processing, and analysis for biological and physical sciences applications.
EELS Imaging & Analysis
The purpose of this school is to inform potential Gatan PEELS and Imaging Filter (GIF) users of the capabilities of parallel-detection electron energy-loss spectroscopy (EELS) and energy-filtered imaging, and to give current users the necessary theoretical background and hands-on training to get the most out of their PEELS or GIF systems.
TEM Specimen Preparation
This extensive, practical course has been designed to teach materials scientists the art and science of TEM specimen preparation. The course will concentrate on the various ion-milling techniques now available and will show how excellent TEM specimens can be produced from almost any material encountered. Special attention will be given to preparation of cross- sections through surfaces and interfaces. The materials used in the laboratory sessions will include semiconductors, metals, ceramics, and their combinations.
April 20-25, 1998 7th Frontiers of Electron Microscopy in Materials Science Conference Irsee Germany Contact: W. E. King, L-356, LLNL, Livermore, CA 94551 E-mail: weking-at-llnl.gov
Please visit the Frontiers of Electron Microscopy in Materials Science Conference website at
http://multiscale.llnl.gov/femms98
------------------ RFC822 Header Follows ------------------ Received: by quickmail.llnl.gov with ADMIN;22 Jan 1997 13:07:48 -0800 Resent-Date: Wed, 22 Jan 1997 13:07:48 -0800 (PST) Resent-From: king-at-cms1.llnl.gov Resent-To: wayne_king-at-quickmail.llnl.gov Received: from pierce.llnl.gov by cms1.llnl.gov with SMTP; Wed, 22 Jan 1997 13:07:48 -0800 (PST) Received: by pierce.llnl.gov (8.6.10/LLNL-1.18/llnl.gov-03.95) id NAA11053; Wed, 22 Jan 1997 13:07:46 -0800 Received: from popcorn.llnl.gov by pierce.llnl.gov (8.6.10/LLNL-1.18/llnl.gov-03.95) id NAA11043; Wed, 22 Jan 1997 13:07:44 -0800 Received: from 128.115.25.7 by popcorn.llnl.gov (8.6.10/LLNL-2.0) id NAA23371; Wed, 22 Jan 1997 13:07:35 -0800 Message-ID: {32E68199.46B4-at-llnl.gov}
on Wed, 22 Jan 97 18:29:00 Jane Glamp wrote:
} Hi Everyone, } I am interested in attending an ultra microtoming class and I need } information about a date, place and cost of an upcoming class if } there = is one. I work in the materials area, not biological. } Thank you very much in advance, } Jane Glamp } glamp-at-ppg.com
} Jane,
AMC Group has offered intensive hands-on workshops on Materials Ultramicrotomy, at basic and advanced levels, twice a year, on a regular basis since 1993. The schedule of the workshops for 1997 is:
Basic Materials Ultramicrotomy May 19-21, =9197 and Nov. 17-19, =91= 97 (Phoenix, AZ) Advanced Materials Ultramicrotomy May 22-23, =9197 and Nov. 20-21 (Pho= enix, AZ)
To receive detailed information about these workshops, please send me yo= ur complete mailing address. Thank you.
Rene E. Nicholas Marketing Director AMC Group (602) 949-4203 Fax (602) 473-9421 **************
AMC Group offers hands-on workshops on TEM Wedge-polishing, FIB-TEM Cross-sectioning, and Materials Ultramicrotomy on a regular basis. =20
Is anyone willing to share their experience in collecting nasal tissue from cynomolgus monkeys?
Perfusion techniques are not an option.
Exact sites of collection are not known to date. I assume we will be collecting from proximal and distal turbinates, and possibly septum.
I Would be interested in any references to methods of collection, fixation. Also would be interested in nasal comparative anatomy of the Rat vs. Monkey.
I was wondering if anyone has tried air-drying plant samples using Hexamethyldisilazane? If so, how successful was it? Our critical point drier is out of commission and I am searching for alternative methods to CPD. If anyone has any other comments or suggestions for drying plant material, I would greatly appreciate it.
Susan Carbyn Atlantic Food and Horticulture Research Station Kentville, Nova Scotia B4N 3R2 Canada
Many thanks to all those who replied to my recent questions about closed circuit cooling systems for electron microscopes. It has been interesting following the subject as, I believe, something so fundamentally simple shouldnt be as complicated as it would seem. I think part of the problem is many people seem to be using locally available products with tradenames that are unheard of elsewhere. It would seem that many of these products are either anti-corrosion or anti-microorganism but often not both. I believe the supplier of the electron microscope should be able to supply the name of a product that is globally available at a reasonable price, or at least supply the name of a product in your area. The additive we were recommended with our last microscope purchase is available to us (from Germany) at a considerable cost. In addition, the supplier of the product recommends regular replacement of the water in the systems, a job I certainly dont want to do.
My questions, just for interest really, to those with closed circuit cooling systems on their microscopes. - What is the name of the anti-corrosion agent you use? - What ratio do you use it at? - How do you replenish it and how often?
- What is the name of the anti-microorganism agent you use? - What ratio do you use it at? - How do you replenish it and how often?
- What is the name of the manufacturer of these products?
TIA,
Allan Mitchell.
Please send responses to allan.mitchell-at-stonebow.otago.ac.nz
Richard Lander, NZCS South Campus Electron Microscope Unit c/- Pathology Department Otago Medical School P.O. Box 913 Dunedin New Zealand. Tel. National 03 479 7301 Fax. National 03 479 7254
Message on behalf of Zyg Poczwa, Scientific Officer in diagnostic EM;
I am requesting help with trying to diagnose a bone marrow biopsy which shows tumor infiltration. The pathologists query whether or not it is megakaryoblastic and consequently would like Platelet Peroxidase (PPO) performed on it. Unfortunately, the only material I have is a Formalin fixed, Paraffin embedded bone marrow specimen.
Has anyone had any experience with doing platelet peroxidase on paraffin embedded tissue?
TIA
Zyg Poczwa.
Richard Lander, NZCS South Campus Electron Microscope Unit c/- Pathology Department Otago Medical School P.O. Box 913 Dunedin New Zealand. Tel. National 03 479 7301 Fax. National 03 479 7254
We generally get very poor results with plant tissue using HMDS } } } } } } } } } } } } } } } } } } } } } } } } } } } } } }
} } I was wondering if anyone has tried air-drying plant samples using } Hexamethyldisilazane? If so, how successful was it? Our critical point } drier is out of commission and I am searching for alternative methods to } CPD. If anyone has any other comments or suggestions for drying plant } material, I would greatly appreciate it. } } Susan Carbyn } Atlantic Food and Horticulture Research Station } Kentville, Nova Scotia B4N 3R2 } Canada } } Phone: (902) 679-5566 } Fax: (902) 679-2311 } } E-mail: carbyns-at-em.agr.ca } } ******************************************************* G.W. Erdos, Ph.D. Phone: 352-392-1295 Scientific Director, ICBR Electron Microscopy Core Lab 218 Carr Hall Fax: 352-846-0251 University of Florida E-mail: gwe-at-biotech.ufl.edu Gainesville, FL 32611 http://www.biotech.ufl.edu/~emcl/ Home of the #1 Gators ***** "Many shall run to and fro, and knowledge shall be increased" Daniel 12:4
} Does anyone have any experience with SEM of reconstituted rat tail collagen
} matrix? The collagen is laid down onto glass coverslips and then cells are
} plated on top of the matrix. I am interested in the collagen more than the
} cells, but can't get any definition of fibers. In some areas there is some
} definition, but the majority of the surface seems compacted with little or
} no definition. I have tried a variety of preparation conditions including
} different fixatives as well as cpd vs. freon for drying. The latter seemed
} to produce the best results, but there is still little definition of the
} matrix.
} I have sputtered for different times, but I still seem to have a problem of
} charging that eventually burns the sample no matter what kV I use. Does
} this
} sound like a preparation problem, an imaging problem, or both? Any help
} would be greatly appreciated.
} Thanks.
} Bill Swaim
Bill,
I have studied the conformation of fibronectin fibrils, which were formed either from fibroblast culture or in cell-free system, using a field emission SEM.
To succeed for high-resolution SEM, you need to preserve structures well in all specimen preparation steps and to reduce beam damage in the FESEM at high magnification. I use cryo techniques: fast-freezing, freeze-drying, cryo-transfer, cryo-coating, and cryo-SEM to achieve the goal.
The images obtained reveal the surface features of fibronectin fibrils and fibronectin molecule at a few nm resolution.
If you have any further questions or want to look at your samples, please feel free to contact me.
Here is a reference list:
Chen, Y., Centonze, V.E., Verkhovsky, A. & Borisy, G.G. (1995) Imaging of cytoskeletal elements by low temperature high resolution scanning electron microscopy. {italic} J.Microsc. {/italic} {bold} 179(1) {/bold} , 67-76.
Chen, Y., Brummel, S. & Peters, D.M.P. (1996) High resolution cryo-scanning electron microscopy in studying of macromolecular structures and assembly of fibronectin fibrils. {italic} Mol.Biol.Cell {/italic} 7(supplement),412a
Chen, Y., Brummel, S. & Peters, D.M.P. (1996) The structure and assembly of fibronectin fibrils studied by high resolution cryo-SEM. {italic} Scanning {/italic} {bold} 18(3) {/bold} , 200-201.
Chen, Y. & Peters, D.M.P. (1997) High resolution cryo-scanning electron microscopy (cryo HRSEM) study of the macromolecular structure of fibronectin fibrils. {italic} Scanning {/italic} , (In Press)
Peters, D.M.P., Chen, Y., Zardi, L. & Brummel, S. (1997) Conformation of fibronectin fibrils varies: discrete globular domains of type III repeats detected. {italic} J.Cell Biol. {/italic} (submitted)
Hope this answers your questions.
Regards,
Ya Chen
Ya Chen
*** My email address has been changed to: ychen14-at-facstaff.wisc.edu ***
We have not been successful in recovering peroxidase activity in parafin embedded tissue. The platelet peroxidase (as apposed to that in neutrophils) is very sensitive. Prolonged fixation will also remove activity. We have been successful at diagnosing M7 (megakaryoblastic leukemia) in peripheral blood using a combination of specific platelet peroxidase staining (using Breton-Gorius's published method) and immunostaining for GPIIb/IIIa (alphaIIb beta3 integrin). This is relatively easy to do and only requires that the peripheral blood have significant numbers of blasts.
Sorry I could not give a more positive answer, but with platelet peroxidase I think you will not be successful with anything other than very fresh tissue.
Jay Jerome ************************************************************** * aka: W. Gray Jerome * * Dept. of Pathology * * Bowman Gray School of Medicine of Wake Forest University * * Medical Center Blvd * * Winston-Salem, NC 27157-1092 * * 910-716-4972 * * jjerome-at-bgsm.edu * **************************************************************
On Fri, 24 Jan 1997, Richard Lander wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } Message on behalf of Zyg Poczwa, Scientific Officer in diagnostic EM; } } I am requesting help with trying to diagnose a bone marrow biopsy which } shows tumor infiltration. } The pathologists query whether or not it is megakaryoblastic and } consequently would like Platelet Peroxidase (PPO) performed on it. } Unfortunately, the only material I have is a Formalin fixed, Paraffin } embedded bone marrow specimen. } } Has anyone had any experience with doing platelet peroxidase on paraffin } embedded tissue? } } TIA } } Zyg Poczwa. } } } Richard Lander, NZCS } South Campus Electron Microscope Unit } c/- Pathology Department } Otago Medical School } P.O. Box 913 } Dunedin } New Zealand. } Tel. National 03 479 7301 Fax. National 03 479 7254 } } "Southernmost EM Unit in the World!" } } }
} K. A. Brackett, Ph.D. wrote: } } "PCM really gives total airborne fiber concentration because asbestos cannot } be differentiated from any other fiber of similar size. } SEM methods rely on EDS for identification but cannot differentiate } asbestos from other mineral fibers with the same chemical composition but } different crystalline structure. } TEM uses both EDS and SAED and is the only method currently acceptable in } law courts in the U.S." }
The difference between the techniques is related to resolution and visibility in addition to the identification mentioned above. There are three common commercial types of asbestos: chrysotile, crocidolite, and Amosite. Single crystal chrysotile asbestos fibers (fibrils) are typically about 40nm wide, crocidolite asbestos has a larger width distribution but fibrils are commonly seen down to about 10-20 nm in width. Single crystals of Amosite are typically thicker than the other two commercial abestos types and may be a few tenths of a micrometer. (note: In all cases length is somewhat independent of the width, so that one can easily have very long-thin fibers.)
Chrysotile and crocidolite, therefore, can have a significant portion of the fibers below the resolution of the phase contrast light microscope (PCM). When analyzed directly on filters, the visibility (not resolution) of these thin fibers using a thermionic gun SEM is also very limited and not reliable for analysis. TEM can easily see/analyze the thinnest asbestos fibers. For Amosite, due to its thicker nature, the resolution/visibility case is more ambiguous and may be sufficient, especially in the SEM case.
Thus, PCM not only counts fibers indiscriminately (adding nonasbestos fibers), it also misses fibers indiscriminately (missing thin asbestos and other fibers). Thermionic gun SEMs have biases that are similar but not quite as severe as the PCM.
The reliability/use of the PCM/SEM/TEM also depends on its application. Asbestos occurs naturally in veins or mats of billions of bundled fibers. Since size fractionation of aerosol particles is a well known phenomenon, the sizes, especially the width, of the asbestos fibers/bundles in an aerosol will vary with location and the processes to which the asbestos has been exposed. Thus different locations/samples will have different size distributions. And different techniques (PCM/SEM/TEM) may get useful or totally useless results depending on the fiber sizes and types and the history of that particular aerosol.
To make the choice of method problem more complex yet ... only occupational (asbestos textile plants and the like) air samples analyzed by PCM have been correlated with health effect.
Again, as Brackett mentioned, the asbestos analysis issue can be very complex.
Eric B. Steel, Leader e-mail: eric.steel-at-nist.gov Microanalysis Research Group Office: 301-975-3902 N.I.S.T. FAX: 301-216-1134 Bldg. 222/Rm A113 Gaithersburg MD 20899
Matthew Stough wrote: } I'd like to find a reference or two on an ALCHEMI } study of an ionic material where atoms A and B } can *not* reside on either of the sites (meaning, } for example, that Zr would not be found on the O } sites and vice versa). } .... } If you are aware of specific ALCHEMI studies on } ionic (and perhaps covalent) materials, I'd appreciate } the reference.
Dear Matthew, To add on the reply from Joergen Bilde-Soerensen: There are two nice references from mineral physics:
Max T. Otten,1989, A practical guide to ALCHEMI, Philips Electron Optics Bulletin, 126, 21 - 28 (and refs therein)
Alex C. McLaren, 199, Transmission electron microscopy of minerals and rocks, chapter 7, Cambridge topics in mineral physics and chemistry, Cambridge University press, Cambridge
} Subject: Monte Carlo Models } } I've got a set of these models on my FTP site, and everyone is } welcome to them. I worked with Dave Joy in the mid '80's to } convert these from Apple basic to IBM Basic. Later I took them } from CGA to VGA resolution. They're compiled Quick Basic. The } source code is not included, since I'm concerned about someone } changing the code and effecting the validity of the results. }
David Joy's Monte Carlo models are also available, including source code in Borland Turbo Pascal ver 5, for example at
Many years ago I tried a variety of anti-corrosion, anti-bug additives, none of which were really satisfactory. On my current microscope, a Jeol 2000, I use distilled water without any additives. The water has not been changed in ten years, only topped up. In the absence of any nutrient bug growth is minimal and there have been no corrosion problems. Regards,
Eric Lachowski
---------------------- Dr Eric E. Lachowski University of Aberdeen Department of Chemistry e.lachowski-at-abdn.ac.uk
I am curious. After 28 years of changing tungsten filaments out in the sticks, and with little contact with the alternatives, what do you really think about LaB6 and FEG sources? This is in case we are successful in getting funding again!
Is FEG reliable or do you still get problems these days - I know in its early days there were some scare stories but how about now?
Any off-line/on-line comments would be appreciated.
Keith Ryan
Plymouth Marine Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, England
e-mail: k.ryan-at-pml.ac.uk
PML web site: http://www.npm.ac.uk/pml ++++++++++++++++++++++++++++++++++++++++++++++++++
} I am curious. After 28 years of changing tungsten filaments out in the } sticks, and with little contact with the alternatives, what do you really } think about LaB6 and FEG sources? This is in case we are successful in } getting funding again!
LaB6 has the great advantage that is has a life much longer than tungsten, therefore the money issue is maybe not so critical. Moreover you would not have to spend so much time in changing cathodes (a LaB6 cathode here lasts from 6 months to one year, to be compared with the 2 weeks for a tungsten one, if the microscope is used full time).
Also it must be emphazised that you get more intensity with LaB6, as well as more coherence of the beam, factors which may be critical for high resolution works.
The main problem may arise if the microscope is used by numerous users, when there is always a risk of someone doing something wrong. And it musr be noted that LaB6 needs "conditioning", meaning that it takes over one day (better a week-end) to have it ready to operate, if nothing gets wrong...
Yves MANIETTE Universitat de Barcelona Serveis Cientifico Tecnics Unitat ESCA TEM Carrer Lluis Sole i Sabaris, 1-3 E-08028 BARCELONA ESPANYA
Hi Susan. I keep an archive of biologic discussions posted to the microscopy list. There are two discussions which you may be interested in. Go to the web address listed at the end of this message and click on the "Tips & Tricks" link. From there go to the SEM section and look for the HMDS and Peldri links. Both should be informative. In answer to your question, HMDS might work. We teach an SEM short course twice a year and we make everyone dry their sample down with both HMDS and CPD to teach them the process and make them aware that different procedures can give different results. So far we have found no rhyme or reason to which plant tissues will work and which won't and we haven't made an attempt to catalog which do. I can't express an opinion on Peldri because we do not use it here. Boss man says it is a pain and that has been good enough for me. Hope this helps.
At 01:50 PM 1/23/97 -0500, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} {} { GO GATORS Scott D. Whittaker 218 Carr Hall Research Assistant Gainesville, FL 32610 University Of Florida ph 352-392-1295 ICBR EM Core Lab fax 352-846-0251 sdw-at-biotech.ufl.edu http://www.biotech.ufl.edu/~emcl/ The home of " Tips & Tricks "
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To: Microscopy ListSer {Microscopy-at-MSA.Microscopy.Com}
Difficulties in getting to my models on AOL have prompted me to move them. You should be able to FTP them from:
http://members.aol.com/dking99/mc
The self un-packing file is; MCVGAPAK.EXE Short instructions are in: MCVGAPAK.DOC
Again, these are based on Dave Joy's mid 80's Apple Basic model. Sorry for any inconvenience this has created. Please let me know how this works, what you think of the code, etc.
Message-Id: {2.2.32.19970124163047.006a3c34-at-po9.mit.edu} X-Sender: tonygr-at-po9.mit.edu X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"
Keith Ryan asks about sources for EM's.
It all depends!!!
The only real advantage of a W source is that it is quite inexpensive to buy. Although changing a W source is relatively quick, I suspect the total down-time compared with LaB6 is comparable, because it has to be done quite often. The W source, of course, cannot begin to touch the performance of the LaB6.
LaB6 and FEG are now mature options. We have 4 LaB6 instruments and 2 FEG's. Premature gun failures are associated only with operator error. (In fact our FEG SEM is 2 years old and has not yet required a new tip, and the HB603 has run for 4 years on the same tip). Some people even question the need to heat LaB6 slowly these days, though we still do it. Our one remaining W microscope will be retired within the next few weeks, and replaced with another LaB6.
I hope this gives a sense of our opinions on the subject!
Tony Garratt-Reed.
**************************************************** **************************************************** ** ** ** Anthony J. Garratt-Reed ** ** Room 13-1027 ** ** Center for Materials Science and Engineering ** ** Massachusetts Institute of Technology ** ** 77 Massachusetts Avenue ** ** Cambridge, Massachsetts 02139-4307 ** ** U. S. A. ** ** ** ** Phone: 617-253-4622 ** ** Fax: 617-258-5286 or 617-258-6478 ** ** ** **************************************************** ****************************************************
We have a venerable LKB III Ultramicrotome in need of repair. The problem resides in the external control unit (swapping out another control unit from another LKB III solves the problem) and has to do with the specimen arm "quivering" rather than rising and falling in an appropriate manner. We have replaced vac tubes to no avail and now believe that professional assistance is warranted. Anyone know of a company or individual who might be of assistance? Thanks.
#################################################################### John J. Bozzola, Ph.D., Director Center for Electron Microscopy Southern Illinois University Carbondale, IL 62901-4402 U.S.A. Phone: 618-453-3730 Fax: 618-453-2665 Email: bozzola-at-siu.edu Web: http://www.siu.edu/departments/shops/cem.html ####################################################################
Susan Carbyn I did a small comparative study several years ago using HMDS, the now out of production Peldri, and CPD. I used renal and bronchial tissue with each treatment. The HMDS was as good as CPD for both tissues, but the fine cilia in the bronchial tissue looked better using the Peldri. I wish they had not taken that off the market. Another investigator working with whole fish (minnows) couldn't get any other drying procedure to work other than Peldri. For soft tissues, the HMDS seemed to have a greater chance of shrinkage artifact but this was not consistent. It did help to increase the number of infiltration steps from ETOH into 100% HMDS. I have heard that you can use Freon 113 as a drying agent but people I have talked to say they were not happy with it's results. Hope some of this helps instead of making it more confusing
Auburn University is seeking an electron microscopist who is experienced in biological electron microscopy and has a working knowledge of current techniques. A working knowledge of and experience with advanced light microscopic techniques are desirable. It is also desirable for the candidate to be able to apply electron microscopy to other fields.
Rank and Salary: Appointment is a non-tenure track research fellow position. The position is a 2-year appointment, renewable upon satisfactory performance and available funding. Salary is commensurate with training and experience.
Qualifications: Ph.D. in the biological sciences with an emphasis in electron microscopy.
Responsibilities: This position involves both research and teaching. The appointee is expected to manage and operate an electron microscope facility that has a Zeiss DSM 940 scanning electron microscope that is equipped with an X-ray unit, a Zeiss EM-10 transmission electron microscope, and ancillary equipment critical point dryer, vacuum evaporator, sputter coater, etc. Assist faculty, staff and graduate students in sample preparation and operation of the electron microscopes. Teach and/or assist in teaching courses in electron microscopy. Collaborate with reseachers and actively participate in writing research proposals and performing research. Write competitive research proposals and conduct original research.. Take the lead role in writing equipment proposals for upgrading the electron microscope facility. Interact well with users of the electron microscope facility and provide outreach to members of the community. Establish a working relationship with and attract funds from industry.
Application: Please send resume and names, addresses and telephone numbers of three
references to:
Christine W. Curtis, Chair, Search Committee Office of the Associate Provost and Vice President for Research 202 Samford Hall Auburn University, AL 36849-5112 (334) 844-4784 (Phone) (334) 844-5971 (Fax) curticw-at-mail.auburn.edu
Review of candidates will begin on February 15, 1997.
Auburn University is an Affirmative Action/Equal Opportunity Employer Minorities and Women are Encouraged to Apply
Columbian Chemicals Company has an immediate opening in the Physics Laboratory section of Laboratory Services located in Monroe, Louisiana. The job responsibilities include materials characterization and research in carbon black morphology and its interaction in vehicle systems (mainly elastomers) using scanning electron microscopy and energy dispersive x-ray analysis (SEM/EDS), scanning tunneling/multi-mode atomic force microscopy (STM/AFM), transmission electron microscopy (TEM), light microscopy and image analysis. We are seeking a candidate with a M.S. or Ph.D. in Carbon Science, Materials Science, Chemistry or Physics with a thorough background in one or several of the above microscopy techniques. Interested candidates should contact or send their resume to:
Dr. Alex Dmytraczenko Director, Laboratory Services Columbian Chemicals Company P.O. Box 96, Hwy 139 South Carbon Road Swartz, LA 71281 (318)329-8021
Columbian Chemicals Company is a subsidiary of Phelps Dodge Corporation and is the second leading produce of carbon blacks in the world with plants in North America, Europe, and Asia. Any interested candidates should be aware that Laboratory Services may be relocating to Marietta, Georgia in the near future.
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I have no idea how many hours are in the two weeks of W filament life but I suspect if it's life is that short you do not have a column vacumn that is low/high? enough for LaB6 or FEG source. Kate Connolly
A fellow researcher has been experiencing possible fixation/dehydration problems using wheat root tissue.
The method being used for our wheat roots is: fix in 2% paraformaldhyde plus 0.8% glutaraldehyde in 0.01 M Na-phosphate buffer overnight, followed by 3 changes of buffer, then 1% osmium for 1 hr, then 3 changes in water, then dehydrated (hold in 70% ETOH overnight), eventually embedding in LR White.
Main problems are:
1. Inconsistent infiltration of tissue
2. Very often get considerable shrinkage and distortion of the cortical tissue
Thank you for any suggestions,
Ginger Baker
Electron Microscopy Lab Manager Department of Anatomy, Pathology, and Pharmacology 250 Veterinary Medicine Oklahoma State University Stillwater, OK 74078 (405) 744-6765 FAX: (405) 744-5275 EMail: lizard-at-okway.okstate.edu
For 4 years RMC and the University of Arizona, Tucson, AZ have sponsored a workshop that has received excellent reviews from the participants, several of whom had attended other similar courses.
The course is typically held in October each year, the dates for this year will be set in February. We will post a second announcement at the time the course dates are set.
This course focuses on actual transfer of skills, not just knowledge. The instructors from each discipline of metals, polymers, thin films and biologicals all work with each student to truly understand the demands of their samples. Knowledge of glass knife making, diamond knife selection and care, types of resins, sectioning variables how to attack special problems are all part of the course.
For a complete prospectus please contact me at RMC, 4400 S. Santa Rita, Tucson, AZ 85714, phone 520-889-7900, fax 520-741-2200, email RMCBTLI-at-AOL.com
Steve Miller Director of Sales, North America Ultramicrotomy Division
At 08:30 24/01/1997 +0000, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America than 4 years with restriction due to a very good vacuum and the necessity to bake the gun once or two time a year. FEG Sem are now used by all people working in electron microscopy with no major problem, the resolution is very good even for low voltage, current is enough to do EDS (not WDS for now or in special condition with sealed counters...) and maintenance rather cheap (just consider the price of filament boxes during 4 of 5 years) FEG Tem are not very common for now because of cost but in term of analytical the machines are fantastic. Hope That helps.
Greetings from soggy California: I would like to know who is still making cryo-ultramicrotomes. With all the mega-mergers these past few years, I've lost track of all the "older" companies except for Reichert-now Leica. Are they still out there under different names? Thanks for your time.
John Hardy E.M. Facility City of Hope Med. Cntr. Duarte, CA (818) 301-8265 jhardy-at-smptlink.coh.org
In message {2E943120.1991-at-okway.okstate.edu} Ginger Baker writes: } To all: } } A fellow researcher has been experiencing possible } fixation/dehydration problems using wheat root tissue. } } The method being used for our wheat roots is: fix in 2% } paraformaldhyde plus 0.8% glutaraldehyde in 0.01 M Na-phosphate } buffer overnight, followed by 3 changes of buffer, then 1% osmium } for 1 hr, then 3 changes in water, then dehydrated (hold in 70% ETOH } overnight), eventually embedding in LR White. } } Main problems are: } } 1. Inconsistent infiltration of tissue } } 2. Very often get considerable shrinkage and distortion of the } cortical tissue } } Thank you for any suggestions, } } Ginger Baker } } Electron Microscopy Lab Manager, Department of Anatomy, Pathology, and } Pharmacology, 250 Veterinary Medicine, Oklahoma State University, Stillwater, } OK 74078, (405) 744-6765, FAX: (405) 744-5275 } EMail: lizard-at-okway.okstate.edu
Ginger,
I'd suggest boosting the glutaraldehyde concentration up to 2-2.5% for better fixation, and increasing the buffer concentratin to 0.1M. Your present buffer of 0.01M is quite low and you don't have much buffering capacity for roots of any appreciable mass. Also, extending dehydration and infiltration times may help. These may help eliminate the shrinkage and poor infiltration.
Under seperate cover, I'll send you technical tips on LR White proceedures that I've gleaned from this forum over the last few years (anybody else want them, please reply privately to my e-mail address).
Good luck!
Gib Ahlstrand, MMS Newsletter Editor Electron Optical Facility, University of Minnesota, Dept. Plant Pathology 495 Borlaug Hall, St. Paul, MN 55108 (612)625-8249 612-625-9728 FAX, giba-at-puccini.crl.umn.edu
"When the mode of the music changes, the walls of the city will shake." - PLATO "There's a whole lotta shakin' goin' on!" - CHUCK BERRY
At 08:30 AM 1/24/97 +0000, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America The only thing I don't see having been mentioned here is your application. If you typically use 10 to 30kV, then there might not be any advantage of FEG over LaB6 unless you can afford the extra expense and want the ease of use. However, at voltages below 5kV you'll notice markedly improved brightness and improved resolution of the FEG over LaB6, and LaB6 over W.
And of course, by extra expense, we mean it isn't that expensive to add an ion pump to the gun region for LaB6, but for FEG you really ought to consider a different instrument.
cheers, shAf
{\/} /\ {\/} /\ {\/} /\ {\/} cogito, ergo ZOooOM {\/} /\ {\/} /\ {\/} /\ {\/} Michael Shaffer, R.A. - University of Oregon Electron Probe Facility mshaf-at-oregon.uoregon.edu -or- mshaf-at-darkwing.uoregon.edu http://darkwing.uoregon.edu/~mshaf/
Has anyone heard of "Wang Biomedical" microscopes ? Apparently thay are made in Holland. I am trying to find out about their reliability and quality.
Please send your responses directly to "cakyol-at-cisco.com" since I am not sure whether my membership request to this e-mail alias has been successfull or not.
In my Microscopy Vendors Database is all information about Wang Biomedical (postal address, phone, fax, e-mail and www address): http://www.kaker.com/mvd/vendors.html
At 11:34 AM 1/24/97 -0600, John J. Bozzola wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
John, We have three vintage LKB's (II and III) and would appreciate any info you obtain regarding service/repair. Rosemary Walsh
At 2:42 PM 1/24/97 -0800, Ginger Baker wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Ginger, You might trying leaving the samples under vacuum overnight during the primary fixation and then prolonging the infiltration steps. It depends on the specimen but you also might take the dehydration past 70% to 85% or further.
In response to all who are selling the idea of total digital photography. We are aware of digital technology, we have it, we use it, we love it. Heck if you have the cash digital image technology comes quite close to that of film. However, I still want to offer traditional darkroom capabilities as well, hence the request for a decent enlarger.
I am in agreement with the logic regarding the move from conventional darkroom to a totally digital lab. Going digital not only saves time in darkroom processing is more flexible, and also has environmental impact as well.
Currently our lab is 80% digital having digital capture from SEM, Image analysis, and partially from TEM. Currently we have two Kodak/Codonic 1600 series Dye sublimation printers. We also have decent CCD cameras, even use a Kodak DCS420 digital 35mm camera for other applications. Routinely we use digital images for publications, etc.
No doubt about it, digital photography has a strong future in electron microscopy and image analysis. However, I still believe there are occasions where traditional photography is the best alternative, especially since we have thousands of negatives in archives that on occasion need quality prints for our customers requesting that service.
Whatever the reason I believe we still have a need for darkroom enlargers for several more years.
For those who are fully digital, quite possibly you might be interested in donating your darkroom enlarger:-).
I would ask why you still need darkroom PRINT capability. With a good CCD with macro lens, you should be able to enlarge any area that you could using a photographic enlarger. However, I do not speak from direct experience, as I've never worked in a lab without a darkroom. However, I'm making a strong push to eliminate photopaper processing at my present place of employment. The basic point to be made is that a good dye sublimation printer can faithfully reproduce any captured image with proper grayscale rendition just as well as a photographic reproduction. Two years ago, however, I could not make the same claim. Thus, I would not recommed spending the $5-10K necessary to purchase a good new enlarger. Rather, invest the money in a high end CCD camera, such as the Kodak MegaPlus, and a decent dye-sublimation printer.
Has anyone heard of "Wang Biomedical" microscopes in Holland ?
I am trying to find out about their reliability, quality etc.
I am buying my first scope and any advice anyone offers will be much appreciated.
I tried to subscribe to the listserver but have not got a confirmation, therefore I'm not sure if I am included in the e-mail alias, so I would appreciate it if responses could be e-mailed to me: jakyol-at-pacbell.net
Gib, I would also be interested in receiving a copy of your accumulated LRWhite tips. Thanks in advance, Janet.
Janet K. Dye Ph. D. Graduate Student, Soils Land, Air, and Water Resources University of California Davis, California USA (916) 752-0199 (916) 668-4217 jkdye-at-ucdavis.edu
I am going to start looking at marine bacteria grown on plates and was wondering if someone had a good protocol for the fixation process. I will be doing SEM so I need to get rid of the salts and maintain cell integrity. I have used 2.5% glut in artificial sea water to fix but even with DH20 washes, I still get a lot of salt on the specimen and the specimen seems to be covered with a "slime" like coating. Is there a way to prevent this? I want to look at the alignment of the bacteria. Thanks for any help.
Peace through Christ,
Phil Rutledge, Director e-mail: prutle1-at-gl.umbc.edu Center for Microscopy voice: (410) 455-3582 UMBC Dept. of Biology fax: (410) 455-3875 Catonsville, MD 21228 ///// / / / / /////// /////// / / /////// /////// / / / / / / / / / / / / /////
I do not have experience with FEG (which I would love to have), but with LaB6, I believe that you can count on the following advantages, in order of importance:
1) Less "downtime" - much cleaner emission source. This also equates to less $$ in the long run, if you consider what your time is worth. 2) Higher EDS count rates. This means you can run at lower kV's and still get reasonable statistics and good analyses; almost a requirement for charge sensitive samples. 3) Higher brightness; again, you can run at lower kV's and get better S/N in your image.
BTW, depending upon your microscope, the cost of LaB6 is rather minimal - about $600. Might be worth the investment. I use one LaB6 source at a time, and use tungsten as my "backup". Works pretty well.
************************************ Bob Citron Chiron Vision 555 W. Arrow Hwy Claremont, CA 91711 USA Email: Bob_Citron-at-cc.chiron.com *************************************
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I am curious. After 28 years of changing tungsten filaments out in the sticks, and with little contact with the alternatives, what do you really think about LaB6 and FEG sources? This is in case we are successful in getting funding again!
Is FEG reliable or do you still get problems these days - I know in its early days there were some scare stories but how about now?
Any off-line/on-line comments would be appreciated.
Keith Ryan
Plymouth Marine Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, England
e-mail: k.ryan-at-pml.ac.uk
PML web site: http://www.npm.ac.uk/pml ++++++++++++++++++++++++++++++++++++++++++++++++++
Message-Id: {3.0.32.19970127094222.00711b48-at-darkwing.uoregon.edu} X-Sender: mshaf-at-darkwing.uoregon.edu X-Mailer: Windows Eudora Pro Version 3.0 (32)
At 10:11 AM 1/28/97 +0400, fams-at-holonet.net wrote: } You actually write nothing, but attach 3 documents (30kb) ... I really do wish people wouldn't send attachments to any list. Please understand that we have to download them whether we want them or not, and if we choose to delete the e-mail (for whatever reason) we ^also^ have to find and delete the attachments. For me, this happens to be easy ... I know where attachments are saved ... but this is not generally true of everyone on a list.
Let me suggest you make the list aware of such announcements, and if anyone responds then you can send them the info ... or (better still) you could make us all aware that these announcements are available at a website ...
We have a penetron swirling shaker and over the weekend, something happened to it. The O-ring inside snapped, and this morning I got it temporarily replaced. Now, when I turn it on, it squeaks real loud! Apparently, it was making this noise over the weekend before it snapped. Does anyone have this type of shaker or have any ideas of how I could quieten this down? Perhaps there is something wrong with it! It is not that old, but I believe that the warranty has run out. I need to use it now but am afraid that I may be doing more damage by letting it run.
Any help or suggestions are welcome! Thanks, Susan
P.S. I want to thank everyone who replied to my HMDS question. I find this news group to be incredibly helpful! Thanks again.
Susan Carbyn Atlantic Food and Horticulture Research Station Kentville, Nova Scotia B4N 1J5 CANADA
At 10:10 AM 1/27/97, rutledge phil wrote: } I am going to start looking at marine bacteria grown on plates and was } wondering if someone had a good protocol for the fixation process. I will } be doing SEM so I need to get rid of the salts and maintain cell } integrity. I have used 2.5% glut in artificial sea water to fix but even } with DH20 washes, I still get a lot of salt on the specimen and the } specimen seems to be covered with a "slime" like coating. Is there a way } to prevent this? I want to look at the alignment of the bacteria. Thanks } for any help.
Phil,
We routinely use 2% glut in 0.1-0.2 M sodium cacodylate. With three washes, post-fix in OsO4, three washes, dehydration in ethanol, and CPD we usually don't have a problem with salt precipitation. The slime could be a mucous coat from the bacteria, therefore might need a prefixation treatment. If your preparation includes the plate media then that could be the problem.
A couple of references:
Watson, LP, AE McKee, and BR Merrell. 1980. Preparation of Microbiological Specimens for Scanning Electron Microscopy. Scanning Electron Microscopy. II: 45-56.
Krueger, DM, RG Gustafson, CM Cavanaugh. 1996. Vertical Transmission of Chemoautotrophic Symbionts in the Bivalve Solemya velum (Bivalvia: Protobranchia). Biological Bulletin. 190: 195-202.
Hope that helps, Louie Kerr
Louie Kerr Research and Education Support Coordinator Marine Biological Laboratory 7 MBL Street Woods Hole, MA 02543 508-289-7273 508-540-6902 (FAX)
We have looked at settlement of marine bacteria (and whatever else) on glass plates, and I use my usual marine invertebrate fix:
4% glutaraldehyde in 0.1M cacodylate with 0.35M sucrose (2.5% glut will probably do)
Wash with 0.1M cacodylate with 0.44M sucrose
Postfix with 1% OsO4 in 0.1M cacodylate (sucrose optional)
Dehydrate with 30% - 100% EtOH as usual, then CPD.
Haven't had trouble with salt sticking around. Slime may or may not be removed - in many cases we WANTED to see the slime (but Murphy's law dictates that it will disappear if that's what we wanted to see). De-sliming seems to take place with thorough dehydration with EtOH (?).
Try to minimize the amount of culture medium that gets fixed onto the bacteria! That may be the culprit.
And remember to wear your lucky red shoes.
Tina
On Mon, 27 Jan 1997, rutledge phil wrote:
} Hi! } } I am going to start looking at marine bacteria grown on plates and was } wondering if someone had a good protocol for the fixation process. I will } be doing SEM so I need to get rid of the salts and maintain cell } integrity. I have used 2.5% glut in artificial sea water to fix but even } with DH20 washes, I still get a lot of salt on the specimen and the } specimen seems to be covered with a "slime" like coating. Is there a way } to prevent this? I want to look at the alignment of the bacteria. Thanks } for any help.
http://www.pbrc.hawaii.edu/bemf/microangelo **************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
} Hi! } } I am going to start looking at marine bacteria grown on plates and was } wondering if someone had a good protocol for the fixation process. I will } be doing SEM so I need to get rid of the salts and maintain cell } integrity. I have used 2.5% glut in artificial sea water to fix but even } with DH20 washes, I still get a lot of salt on the specimen and the } specimen seems to be covered with a "slime" like coating. Is there a way } to prevent this? I want to look at the alignment of the bacteria. Thanks } for any help.
The slime is normal. Crang & Klomparens _Artifacts in Biological Electron Microscopy_ discusses this, and ways to avoid it. Avoiding sea salts is different. You might try washing with a sucrose solution adjusted to the same osmolarity as the sea water you're using, then washing with DDH2O. If you're not having problems with osmium precipitation after washing with sea water, you could do extended DDH2O washes after the OsO4--osmolarity is no problem (or less of one) after the Os. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
I am surprised that there have been so many comments from folks about different electron sources *in general*, without reference to the specific electron microscope Keith is using. LaB6 requires a better vacuum than tungsten (10 -6 torr or better) and FE requires a *much* better vacuum. Keith's EM must have this capability available to it for him to consider other sources than tungsten. As several folks have pointed out, the benefits also depend a great deal on the sort of work he is doing. The basic "rules of thumb" are that LaB6 is potentially 10 times brighter than tungsten, and that the cost of a source is about US$1.00/hour (these are very broad generalizations; your own "mileage" may vary...).
I would like to call attention to the fact that there is another option to be considered, even on an instrument with relatively poor vacuum: the use of a pointed tungsten filament to increase brightness.
Disclaimer: Energy Beam Sciences manufactures a range of proprietary pointed tunsgten filament tips for most EMs.
Best regards, Steven E. Slap, Vice-President ******************************** Energy Beam Sciences, Inc. Adding Brilliance To Your Vision ebs-at-ebsciences.com http://www.ebsciences.com/ ********************************
At 02:48 PM 1/27/97 -0500, Beth Richardson wrote: } Awhile back someone posted a message about a web site that listed used EM } equipment. Does anyone still have the address?
This information is available at the MicroWorld Resources and News web site, which is located at the URL:
http://www.mwrn.com
Best regards, Steven E. Slap ******************************** Energy Beam Sciences, Inc. Adding Brilliance To Your Vision ebs-at-ebsciences.com http://www.ebsciences.com/ ********************************
Our Website lists over 80 products and is fully hyperlinked to manufacturer's e-mail and websites. It is http://www.shore.net/~catalogs
Call if you would like a copy of the current catalog.
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Elinor Solit Director of Publications The Microscope Book
On Mon, 27 Jan 1997, Beth Richardson wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } Hi, } Awhile back someone posted a message about a web site that listed used EM } equipment. Does anyone still have the address? } TIA } Beth } } ************************************** } Beth Richardson } EM Lab Coordinator } Botany Department } University of Georgia } Athens, GA 30602 } } Phone - (706) 542-1790 } FAX - (706) 542-1805 } Email - beth-at-dogwood.botany.uga.edu } ************************************** } }
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MSA Professional Technical Staff Award
The Microscopy Society of America (MSA) and the MSA Technologists' Forum are the sponsors of the Professional Technical Staff Awards (PTSA) to provide assistance on a competitive basis to full-time professional staff who submit papers for presentation at Microscopy and Microanalysis '97. The PTSA consists of free full registration for the meeting, a copy of the Proceedings and the Sunday evening social event at the Rock and Roll Hall of Fame. In addition, MSA will reimburse awardees up to $600.00 for travel, lodging and other expenses. It is the intent of this award to stimulate attendance for those who ordinarily might not participate, and to encourage employers to support their staff in professional activities. Applicants must have been full paid-up members of MSA for 3 years prior to the time of the meeting. Awards are based upon the quality of the paper submitted for presentation at the meeting. Abstracts will be judged by the MSA Technologists' Forum. The applicant must be the first author of the submitted paper. There will be four awards, two each in the Biological and Physical sciences. Successful applicants must present their papers personally at the Meeting in order to receive the award. Former winners will not be eligible for another award. Applications shall consist of (1) a photocopy of the completed Abstract and Data Form, originals of which can be found in the M&M '97 Registration Bulletin and Call for Papers, to be sent to the Technologists' Forum for judging on or before March 1, 1997. Judgment will be made and awardees notified to submit an original Abstract and Data Form by March 15, 1997. Those not receiving awards will also be notified in time to submit an Abstract and Data Form by March 15, if desired. (2) A supporting letter from the applicant's employer, manager or supervisor, attesting to the applicant's status as a full-time, professional staff member. Send a copy of the completed Abstract and the completed Data Form (copies only, no originals please), along with the supporting letter from your employer, manager or supervisor, to arrive by March 1, 1997, to Beverly E. Maleeff, Chair, MSA Technologists' Forum, SmithKline Beecham Pharmaceuticals, Toxicology-US, Mail Code UE 0462, 709 Swedeland Road, King of Prussia, PA 19406; Phone 610/270-7987; Fax 610/270-7202; E-mail Beverly_E_Maleeff-at-sbphrd.com.
} Subject: W, LaB6 and FEG sources } Author: Keith Ryan {KPR-at-WPO.NERC.AC.UK} at SMTP } Date: 1/24/97 8:30 AM } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Keith,
After working with a good FEG, you will really like it. The FEG tip of our Hitachi S-900 in Madison was almost 10 years old. It was very stable, you can easily obtain a resolution test image at magnification of 350kx-400kx. That means that you have no down time for filament change, high brightness, high resolution. The key factor for FEG is a GOOD vacuum. We flash the tip every 2-3 days, that saves the life of FEG a lot. It was just replaced last week due to the extraction voltage went up.
Best regards,
Ya Chen
Ya Chen
========================================================================= \ / Integrated Microscopy Resource (IMR)-- \ / __ an NIH Biomedical Research Resource TEL : 608-263-8481 \/ / / University of Wisconsin-Madison FAX : 608-265-4076 / / / 1675 Observatory Drive #159 Email1:ychen14-at-facstaff.wisc.edu / /__/_ Madison, WI 53706 Email2:chen-at-calshp.cals.wisc.edu ========================================================================= IMR WWW Home Page: http://www.bocklabs.wisc.edu/imr.html
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I have about $2300 to buy a writable CD system for a high end Mac = computer. Does anyone have any experience with any of these systems for = things like reliability, longevity, etc. We deal with lots and lots of = images and the Jazz and Zip drives get too expensive for the students = when storing many images. Thanks Judy M
Judy Murphy, PhD Microscopy Technology Center San Joaquin Delta College 5151 Pacific Ave Stockton, CA 95207
Phone: 209/474-5284 FAX: 209/474-5600 e-mail: murphy-at-sjdccd.cc.ca.us program web page: http://www.sjdccd.cc.ca.us/ElectMicro/sjdc.html
Carolina Workshop on: LIGHT MICROSCOPY FOR THE BIOMEDICAL SCIENCES June 1-6, 1997 University of North Carolina at Chapel Hill
Instructors: John J. Lemasters Edward D. Salmon Brian Herman ------------------------------------------------------------------- LIGHT MICROSCOPY FOR THE BIOMEDICAL SCIENCES is an introduction to applications of light microscopy. Students will have opportunities for extensive hands-on experience with state-of-the-art equipment for optical imaging, digital imaging processing, fluorescence microscopy and confocal microscopy guided by experienced academic and commercial staff. The course is divided into three major sections with lectures and laboratory exercises on: 1) geometric and wave optics of image formation, microscope alignment, phase contrast and reflection interference contrast microscopy; 2) video imaging, including contrast enhancement by analog and digital image processing, fluorescence microscopy, image detectors, fluorescent probes, ion imaging, and green fluorescent protein; and 3) laser scanning confocal microscopy emphasizing live cell imaging and 3-dimensional image reconstruction. Students are encouraged to bring their own specimens for analysis.
The workshop on LIGHT MICROSCOPY FOR THE BIOMEDICAL SCIENCES will cover basic concepts of light microscopy and introduce several advanced techniques relevant to modern cell and molecular biology. A commercial staff representing leading microscopic manufacturers will make available for student use the latest and most advanced instrumentation for light microscopy, image detection and computerized image analysis. Tuition is $950. ------------------------------------------------------------------- APPLICATION FORM Carolina Workshop on LIGHT MICROSCOPY FOR THE BIOMEDICAL SCIENCES
Position:
Address:
Telephone:
Fax:
Please return this form along with a brief letter describing your research interests and a curriculum vitae. Applicants should contact the program as soon as possible. Full consideration will be given to applications received by April 18, 1997.
Send application to: Dr. Wayne Litaker, Director of Workshops University of North Carolina at Chapel Hill Program in Molecular Biology & Biotechnology CB# 7100, 442 Taylor Hall Chapel Hill, North Carolina 27599-7100 Tel: (919) 966-1730 Fax: (919) 966-6821 e-mail: litaker-at-unc.med.edu ------------------------------------------------------------------- About Carolina Workshops: CAROLINA WORKSHOPS are intensive hands-on laboratory courses designed to teach cutting edge methods in molecular biology and biotechnology. Several courses on different topics in molecular biology and biotechnology are offered each year by the Program in Molecular Biology & Biotechnology at the University of North Carolina at Chapel Hill. Most participants in the Carolina Workshops already hold M.D. or Ph.D. degrees or are advanced pre-doctoral students. The courses are designed for novice students as well as for individuals with prior experience. All students benefit from in-depth interaction with instructors. ------------------------------------------------------------------- About the Instructors: John J. Lemasters, M.D., Ph.D. (Course Director): Dr. Lemasters is Professor and Director of Confocal Imaging in the Department of Cell Biology & Anatomy. Dr. Lemasters' research interests center on toxic and hypoxic injury, liver preservation for transplantation and mitochondrial calcium homeostasis, using confocal microscopy to monitor ions, membrane potentials, cell volumes, oxygen radicals and other parameters in single living cells.
Brian Herman, Ph.D: Dr. Herman is Professor and Co-Director of the Digitized Video Microscopy Facility in the Department of Cell Biology & Anatomy. Dr. Herman's research addresses the role of calcium, tumor suppressor genes, and anti-apoptotic proteins on regulation of cell growth and cell death using techniques of digital ion imaging, resonance energy transfer, confocal microscopy and fluorescence life time imaging.
Edward (Ted) D. Salmon, Ph.D: Dr. Salmon is a Professor in the Department of Biology whose interests are cell biology, cell motility, microtubules and mechanisms of mitosis and cell division. Dr. Salmon's research applies high resolution video and digital imaging microscopy towards understanding the molecular mechanisms governing the assembly of spindle microtubules and the segregation of chromosomes during mitosis. ------------------------------------------------------------------ Carolina Workshop on: LIGHT MICROSCOPY FOR THE BIOMEDICAL SCIENCES June 1-6, 1997 University of North Carolina at Chapel Hill
Instructors: John J. Lemasters Edward D. Salmon Brian Herman ------------------------------------------------------------------- {End of Announcement}
Yesterday I posted a message about the fixation of marine bacteria. I guess I should have added that the bacteria is being grown on agar in 9cm petri dishes. What I want to look at is the association of the bacteria to each other without disturbing the colony. There seems to be a particular orientation and I want to observe this by SEM without taking the bacteria off of the medium. Any suggestion? I appreciate all of the help so far, many thanks.
Peace through Christ,
Phil Rutledge, Director e-mail: prutle1-at-gl.umbc.edu Center for Microscopy voice: (410) 455-3582 UMBC Dept. of Biology fax: (410) 455-3875 Catonsville, MD 21228 ///// / / / / /////// /////// / / /////// /////// / / / / / / / / / / / / /////
} Date: Fri, 10 Jan 1997 08:26:57 -0700 } To: geoffa-at-amsg.austmus.gov.au (GeoffA) } From: george.braybrook-at-ualberta.ca (George Braybrook) } Subject: mucus removal } Cc: Microscopy-at-Sparc5.Microscopy.Com } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America=20
I know this is old mail but can you explain why EDTA should not be used to= =20 decalcify specimens with bone?
Bob Schmitz
}
rschmitz-at-uwspmail.uwsp.edu or rschmitz-at-macsrv1.uwsp.edu=20 (note its macsrv"one" not "el") Robert (Bob) J. Schmitz Department of Biology,=20 University of Wisc. Stevens Point. Stevens Point, Wisconsin 54481 ph 715-346-2420
} Yesterday I posted a message about the fixation of marine bacteria. I } guess I should have added that the bacteria is being grown on agar in 9cm } petri dishes. What I want to look at is the association of the bacteria } to each other without disturbing the colony. There seems to be a } particular orientation and I want to observe this by SEM without taking } the bacteria off of the medium.
You should be able to process them _in situ_ by puddling the solutions on the colonies, exchanging them by careful pipetting. After drying, dissect away sample areas and thin the underlaying agar. Leaving the contents of the dishes intact in the dishes during processing should reduce or eliminate distortion/curling during drying. This assumes drying from HMDS. For CPD, dissect under 100% EtOH. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
} I have about $2300 to buy a writable CD system for a high end Mac } computer. Does anyone have any experience with any of these systems for } things like reliability, longevity, etc. We deal with lots and lots of } images and the Jazz and Zip drives get too expensive for the students when } storing many images. } Thanks } Judy M
Judy, This may be a case where you want to wait a year. The DVD discs are starting to come out now, with the 2nd generation late this year or next year. Don't get 1st generation--the standards for F2 is already known and incompatible with F1. DVD will likely replace CD-ROMs in a few years. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
} } I have about $2300 to buy a writable CD system for a high end Mac } } computer. Does anyone have any experience with any of these systems for } } things like reliability, longevity, etc.
{SNIP} } Judy, } This may be a case where you want to wait a year. The DVD discs are } starting to come out now, with the 2nd generation late this year or next } year. Don't get 1st generation--the standards for F2 is already known and } incompatible with F1. DVD will likely replace CD-ROMs in a few years. } Phil
Can you please explain what DVD media is please......are they comparable to mini-discs?
Thanks, Adam. ''~`` ( o o ) _____________________.oooO--(_)--Oooo._______________________________________ Adam Vivian-Smith PhD Student CSIRO/ University of Adelaide Voice: +61 08 8303 8627 Division of Horticulture Fax : +61 08 8303 8601 Urrbrae, Adelaide Email: Adam.Vivian-Smith-at-adl.hort.csiro.au S.A., 5064 AUSTRALIA .oooO ( ) Oooo. ________________________\ (____( )_________________________________________ \_) ) / (_/
Susan Carbyn wrote: ================================== We have a penetron swirling shaker and over the weekend, something happened to it. The O-ring inside snapped, and this morning I got it temporarily replaced. Now, when I turn it on, it squeaks real loud! Apparently, it was making this noise over the weekend before it snapped. Does anyone have this type of shaker or have any ideas of how I could quieten this down? Perhaps there is something wrong with it! It is not that old, but I believe that the warranty has run out. I need to use it now but am afraid that I may be doing more damage by letting it run. ================================================= SPI Supplies has been selling this product for roughly fifteen years and this is the first time I have heard of this (actually any) problem with it. Also, it is hard to diagnose just what the problem is without seeing the unit. However since this is perhaps about the most expensive shaker of this type money can buy, it would certainly be worth fixing. Let us know if you would like us to take a look at it. Unless the unit has been dropped, I am sure it would be more than worth repairing.
Chuck
====================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
Look for us! ############################ WWW: http://www.2spi.com ############################ =====================================================
} We deal with lots and lots of } } images and the Jazz and Zip drives get too expensive for the students when } } storing many images.
We had the same problem with students and buy a Sony CD-R (2X). The CDs does not cost so much (About $10). The price of the CD-R was $1000 for about 1 year ago.
Gary...
On Tue, 28 Jan 1997, Philip Oshel wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } } I have about $2300 to buy a writable CD system for a high end Mac } } computer. Does anyone have any experience with any of these systems for } } things like reliability, longevity, etc. We deal with lots and lots of } } images and the Jazz and Zip drives get too expensive for the students when } } storing many images. } } Thanks } } Judy M } } Judy, } This may be a case where you want to wait a year. The DVD discs are } starting to come out now, with the 2nd generation late this year or next } year. Don't get 1st generation--the standards for F2 is already known and } incompatible with F1. DVD will likely replace CD-ROMs in a few years. } Phil } } &&& Illigitimi non carborundum &&&&&&&& } Philip Oshel } Station A } PO Box 5037 } Champaign, IL 61825-5037 } (217)244-3145 days } (217)355-3145 evenings } oshel-at-ux1.cso.uiuc.edu } *** looking for a job again ****************** } }
To: george.braybrook-at-ualberta.ca Cc: microscopy-at-Sparc5.Microscopy.Com
Phil, regarding your statement...
} This [i.e., buying a writable CD drive] may be a case where you want to } wait a year. The DVD discs are } starting to come out now, with the 2nd generation late this year or next } year. Don't get 1st generation--the standards for F2 is already known and } incompatible with F1. DVD will likely replace CD-ROMs in a few years.
...but will the drives be able to *write* (not just read) the current CD standard? If you want to distribute info widely (rather than just archiving), which Judy apparently wants to do, you don't want to do it on DVD until most people have access to drives that can read them.
On Tue, 28 Jan 1997, Robert Schmitz, Biology wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } -----------------------------------------------------------------------. } } } EDTA fell out of favour as a decalcifier some time ago. } } I know this is old mail but can you explain why EDTA should not be used to } decalcify specimens with bone? } } Bob Schmitz } I'd like to konw the answer to this too, as we use EDTA to decalcify bone of the otic capsule routinely in inner ear histology. However, we are usually not interested in the bone itself, but the tissues it encapsulates.
Karen Pawlowski Inner Ear Histology UT Dallas/UT Southwestern Med. Ctr.
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Dear All, Thanx for all the input. Here is a summary of that input, info from Parker and my own observations.
The most often-mentioned method to flatten o-rings was boiling. This method worked very well with viton. The advantages of boiling are that the method is easy to do reproducibly, and "It also drives out a lot of 'glup,' to use the technical term. (J. Pawley)". The disadvantage is that the water must then be removed. For viton, this is pretty easy, since that elastomer can be baked out at ~200 C. Another popular method was heating to 50 C in an oven. This was not quite high enough for viton, which did not lay flat after an overnight heating at that temp. I'm sure that heating at a somewhat higher temp would do it, however. The advantages of the oven method are that one need not remove water, and it is the best-controlled method for those elasto- mers, such as buna-N and fluorocarbons, which cannot be heated above 70 C. Following the heating process, one can cool the o-ring either slowly or rapidly. Slow cooling works for me, but there may be situations where shock cooling would be advantageous. In particular, to shape an o-ring to a particular non-flat or non-round configuration, it might be good to heat, shape, then shock-cool. The opposite suggestion--to put the o-ring around a beaker and freeze it in the round state--would not be applicable for my purpose. The reassembly of the column takes so long that the o-ring would thaw and fall out; furthermore, there would be condensation. I can imagine situa- tions where it could be useful to shape an o-ring, freeze it, and install. Spring clips were also suggested for holding the o-ring in place. This also would not be suitable for my situation, but might be useful to consider. A caution about silicone o-rings was that they are very permeable to He. As a result, leak-checking can give false positives for several days. Both viton and silicone o-rings can be baked out at ~200 C, and that may be a good idea for a standard practise, since it will drive off volatiles in the o-rings. Buna N and fluorocarbon cannot be heated above 70 C, and that for only a few hours. Buna N just melts, but fluorocarbon decomposes. Ethylene-propylene is the most radiation-resistant of the common elastomers. We use it for seals which are close to the beam, and it remains relatively flexible under circumstances where either viton or neoprene harden. The Parker O-Ring Handbook is a useful source of info about many properties and applications of various available elastomers. Since elastomers are treated by crosslinking and with additives, and are, no doubt, optimized for particular applications, the appropriate temps and times for particular treatments should be determined experimen- tally, rather than relying on info from books. Some info--such as decom- position temps--can be obtained reliably from books and used to set upper limits for trial runs, but even in this case, it is probably better to talk to the manufacturer before approaching these limits, since the treat- ments may significantly change them.
As usual, the list was a great source of info. Thanx, Nestor, for establishing and maintaining it. Yours, Bill Tivol
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Phil, regarding your statement...
} This [i.e., buying a writable CD drive] may be a case where you want to } wait a year. The DVD discs are } starting to come out now, with the 2nd generation late this year or next } year. Don't get 1st generation--the standards for F2 is already known and } incompatible with F1. DVD will likely replace CD-ROMs in a few years.
} } ...but will the drives be able to *write* (not just read) the current CD } } standard? If you want to distribute info widely (rather than just } } archiving), which Judy apparently wants to do, you don't want to do it on } } DVD until most people have access to drives that can read them.
} } Alfred
The issue of access to read the disks is why we decided to use CD-R's instead of Zip drives or other storage media. Nearly everyone has a CD player for retrieving data and the one recorder (Optima 650) can be moved around for recording. We are fairly happy with this recorder but it seems to me that I get more recording errors than I would like (2 or 3 image files per 50 need to be individually recorded or otherwise manipulated, but these are mostly Photoshop files and these problems may be confined to that type). Not having wider experience with CD-R's I don't know if it is more or less than typical.
Can anyone help locate a proceedure for staining a whole chick embryo with Alizarin Red? We did find something for sectioned material (Dahl's Method for Calcium) but wonder if there is a specific protocol for whole tissues, perhaps with a tissue clearing step. Thanks, Linda Fox lfox1-at-wpo.it.luc.edu Loyola University Medical Center Maywood Illinois
Concerning the question about ignition of organic diffusion pump oils:
Most organic compounds will ignite if heated to a sufficiently high temperature, and there are specific tests designed to characterize this property. It has been more than 50 years since I worked on such matters, but as I recall the most common test involves heating the fluid in an open dish over a bunsen burner, in a well-specified configuration, and noting the temp at which it catches fire. Most manufacturers provide flash point data in the literature for their DP oils. Here are values I found in my files for a few common DP oils: Convoil-10 190 C; Convoil-20 217 C; Octoil-S, 209 C; DC-704, 221 C; DC-705, 243 C; Alcatel 22, 280 C; Santovac-5, 288 C; Neovac SY, 230 C; the perfluorinated Krytox and Fomblin fluids, completely non flammable. Interestingly, these values are comparable to the boiling temperatures for these fluids at a pressure of about 100 Pa, where most DPs operate (see Vacuum Methods in Electron Microscopy, p. 181); however, I have never heard of the oil in a DP igniting under ordinary (and even some rather extraordinary) conditions of use and misuse. Even if it did, the fire would be relatively well confined and could be easily extinguished by placing something over the throat of the pump to exclude air.
Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:313-763-4788; Ph:313-764-3321
I have not been aware that corrosion (i.e. the dissolving away of metal in an aqueous medium) was much of a problem in the cooling systems of most electron mocroscopes and related instruments. It was my impression that such suystems are usually constructed of metals such as stainless steel and copper, which are quite resistant to corrosion under ordinary operating conditions. This has certainly appeared to be the case for the dozen or so instruments I have dealt with over the last several decades. That is, all we have done is to use ordinary distilled water (which we usually bought from a local drug store or grocery store, where it is stocked for people to use in steam irons) in our recirculating cooling systems, and we did this mainly to reduce the formation of mineral deposits, such as might result from the use of ordinary tap water. If you are experiencing evidence of corrosion, such as having the water become 'rusty', I would recommend that you check to see if someone has installed an ordinary steel coupling or other fixture somewhere in the system where it is in contact with one of the more inactive metals such as Cu or StSteel. In that case such metal-to-metal contact would form a galvanic cell that would lead to fairly rapid corrosion of the ordinary steel part. All you should need to do is to replace this steel part with a comparable part made of the metal with which it is in contact. This would eliminate the galvanic cell and the corrosion.
Control of the growth of algae is discussed in some detail in 'Vacuum Methods in Electron Microscopy' (p. 216). As noted there, we have had good success using the compound Chloramine-T (the sodium salt of N-chloro-p-toluenesulphonamide) at the level of about 0.25 gram per liter. This compound is not exceedingly expensive and is commonly available from specialty chemical companies such as Polysciences, Aldrich and Sigma. Excluding light from all parts of the circulating system also helps supress algal growth (i.e. don't use transparent plastic tubing). We have only changed the water when it looked dirty or happened to develop noticable amounts of algal growth. Others have recommended controlling algal growth by: adding enough sodium borate to raise the pH to a value of 9 (making the water alkaline in this way would also supress corroison of iron parts); the use of Dichlorophene (2-2-methylenebis-P-parachlorophenol); and the use of a compound called 'Aqua Treat', available from Aqua Labs (508-388-3989). I have had no direct experience with these latter three methods. Good luck,
Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:313-763-4788; Ph:313-764-3321
I seem to remember that in December there was a group of replies to someone who asked if it was possible to prepare bone for TEM without decalcifying it. As luck would have it, I now have a P.I. asking about that very subject. From what I remember, my impression was that it was possible to prepare bone samples without any special procedures being needed. Did I remember correctly?
I am also interested in staining for calcium. My subject is Douglas Fir ectomycorrhizal with a basidiomycete fungus, Rhizopogon vinicolor. I am trying to localize calcium in the fungal tissue and in the interface area between the plant and the fungal cells. Tracers for calcium have proven difficult, i.e. flourescent probes for calcium do not cross fungal membranes and are probably too large to pass through cell walls as calcium does. I am interested in references on Alizarin red, or "Dahl's method for Calcium", whether these are applicable to botanical specimens, and what about fixing the calcium in place so that it is not displaced by sectioning, etc., prior to staining? Thanks in advance for any advice.
Janet K. Dye Ph. D. Graduate Student, Soils Land, Air, and Water Resources University of California Davis, California USA (916) 752-0199 (916) 668-4217 jkdye-at-ucdavis.edu
I'd recommend going with a CD-writer too, for the following reasons;
1) Your clients (students, faculty members, etc) are MUCH more likely to have immediate access to a CD reader than a DVD.
2) CD standard won't dissappear in a hurry because the whole music industry is locked in on it. It's probable that DVD's will read 'old' CD's too.
3) Assuming a micrograph is around 1MB in size, a CD will hold approx. 600 micrographs - more than enough already. Why would a student, working on your average sized project, want a DVD that holds 4,000-20,000 micrographs? Of course it's a different matter for archiving within the EM lab.
4) I don't know the cost of a DVD witer, but I bet it's a LOT more than a CD writer. You've got the money for a CD writer now. Why wait til you can afford a DVD?
Geoff Avern Microscopy Labs Australian Museum Sydney, Australia
Philips CDD 522 - we're very happy with it. (Usual disclaimer)
} Can you please explain what DVD media is please......are they comparable to } mini-discs? } } } Thanks, Adam.
DVD is the new standard for multigiga byte storage. CD-ROMs with multiple layers of data. The 1st generation is about 4GB, the 2nd about 9GB. I believe they'll be about the same diameter as CDs. Not comparable to mini-discs. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
At 08:58 29/01/1997, Alfred Kracher wrote: } Phil, regarding your statement... } } } This [i.e., buying a writable CD drive] may be a case where you want to } } wait a year. The DVD discs are } } starting to come out now, with the 2nd generation late this year or next } } year. Don't get 1st generation--the standards for F2 is already known and } } incompatible with F1. DVD will likely replace CD-ROMs in a few years. } } ...but will the drives be able to *write* (not just read) the current CD } standard? If you want to distribute info widely (rather than just } archiving), which Judy apparently wants to do, you don't want to do it on } DVD until most people have access to drives that can read them. } } Alfred
True. As far as I know, the 1st generation of DVDs will be read-only or if writable, then only to 1st gen DVD. 2nd gen DVD will read & write only 2nd gen DVD. Current CD-ROM will only read & write to current CD-ROM. Except probably not to all current CD-ROM; as they go to 12X (maybe even 8X) they're changing what they hold constant: the angular velocity or the data density. Currently CD-ROMs change speed as they read from inside=} out. The "faster" ones hold the rotation speed constant, as I recall. Anyway there is/will be compatibility problems between {6-8X CD-ROMs & (8?) 12X and higher ones. Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
} Can anyone help locate a proceedure for staining a whole chick embryo } with Alizarin Red? We did find something for sectioned material } (Dahl's Method for Calcium) but wonder if there is a specific } protocol for whole tissues, perhaps with a tissue clearing step. } Thanks, Linda Fox
Linda, _Staining Procedures_, 3rd ed. Pg.137ff. Biological Stain Commission, Williams &Wilkins Co. Baltimore. 4th ed. has it also, but don't know the page. This work is likely on a higher edition by now. Email me if you need the detailed recipe. Hi to John! Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
This is possibly a very dumb question, but anyway:-
If the carbon coating on a sample is imperfect, or if the earthing from said coating is imperfect, so that the sample charges, is the resulting charge positive or negative? My initial assumption was that is would be -ve (buildup of all those bombarding electrons with nowhere to go), but then surely one 15kV electron produces more than one secondary, doesn't it? I've recently had an incident whereby I got EPMA analytical totals which were a bit high (101 to 103), and this went away when I was more liberal with the conductive paint. Could this be because the sample was charging +ve, thus increasing the effective accelerating voltage?
cheers
Ritchie
Ritchie Sims phone: 64 9 3737599 ext 7713 Department of Geology fax: 64 9 3737435 University of Auckland Private Bag 92019 Auckland New Zealand
The Alizarin technique for calcium is called "Dawsons" and is quite old. We don't have the original reference, but for bone the proceedure is: fix in 10% NFS, wash then transfer to 0.5% aq KOH to which enough alizarin red S has been added to turn solution to deep purple, leave for 24 hours or till bones are distinctly red, transfer thro KOH-glycerine series,3:1, 1:1, 1:3, to pure glycerine. Store in pure glycerine plus few crystals of thymol. Refs for meth blue plus alizarin red staining of bone may help: Bechtol 1948 Stain Technol 23, p3-9; Burdi and Flecker 1968 Stain Technol 43, p47-48; Lundvall 1927 Anat Anz 62, p353-373. If you still require more info, contact me via e-mail and we will try to help.
Miss A.J.Wilson Electron Microscope Unit St George's Hospital Medical School Cranmer Terrace Tooting London SW17 ORE Tel: 0181 725 5220
We found Dawson's original technique for alizarin preparations:
1. Fix in 95% ALC for 48-72Hrs. Prolonged fix in alcohol renders tissue less liable to maceration.
2. Remove fats in acetone for 2-4 days then return specimens to alcohol for 12-24 hrs.
3. Place in 1% KOH until bones or digits appear thro' muscle Transfer to 0.1% Alizarin Red S in 1% KOH. (Other stains eg alcian blue, or victoria blue can be used to counter-stain cartilage or bone at this stage.)
4. Leave till stained or desired bone colour, change to fresh stain if necessary.
5. CLEARING Place in solution of 1g KOH, 20mls glycerine, 79mls dist water, leave till sample clears.
6. When clear, pass thro' increasing conc of glycerine, 50, 70, 90, 100%
Miss A.J.Wilson Electron Microscope Unit St George's Hospital Medical School Cranmer Terrace Tooting London SW17 ORE Tel: 0181 725 5220
The "Advertisement For Applications Engineers" has an unreadable attachment. It appears to be a Wordpro document which I cannot handle. Please repost the message without using attached files.
} This is possibly a very dumb question, but anyway:- If you don't know the answer and you want to know it, then no question is dumb.
} My initial assumption was that is would be -ve (buildup of all } those bombarding electrons with nowhere to go), but then surely one } 15kV electron produces more than one secondary, doesn't it? } I've recently had an incident whereby I got EPMA analytical } totals which were a bit high (101 to 103), and this went away when I } was more liberal with the conductive paint. } Could this be because the sample was charging +ve, thus } increasing the effective accelerating voltage?
The only way the sample can charge up is if the BSE and SE current is more than the incident current. It is my understanding that for flat non-conducting samples that this situation occurs around 1kV, slightly less than the charge balancing condition for LVSEM. At higher voltages, the sum of the backscatter coefficient and secondary electron coefficients will be significantly less than one. If the sample is tilted to high angles (e.g., 70 deg), then the charge balance condition can be extended to about 3keV. But you wouldn't be tilting your sample to such high angles for analysis.
I think the answer to your increased signal may lie in the cross section for core ionization with overvoltage. If your sample charges negatively, then the overvoltage will decrease. The cross section for ionization increases as the overvoltage decreases. (It has a maximum at about 2.5-3.) Test this. When you have a good sample that is behaving properly, reduce the beam voltage a little and keep the probe current constant and see if the counts go up. - -Scott Walck
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} } ...but will the drives be able to *write* (not just read) the current CD } } standard? If you want to distribute info widely (rather than just } } archiving), which Judy apparently wants to do, you don't want to do it on } } DVD until most people have access to drives that can read them. } } } } Alfred
I read an recent article about the development and marketing of DVD disks and drives. The introduction of writeable DVD drives is planned only for next year and of course it will take some time until they become affordable.
Petra -------------------------------------------------------------- Dr. Petra Wahlbring Centre de Recherche Public Centre Universitaire (CRP-CU) Laboratoire d'Analyse des Materiaux (LAM) 162a, av. de la Faiencerie L-1511 Luxembourg tel. +352-466644-402 fax +352-466644-400 e-mail: petra.wahlbring-at-crpcu.lu or 100112.2335-at-compuserve.com
I, too, would be very interested in any first hand information or references available regarding the decalcification of bone - EDTA, ascorbic acid, or other.
Pat Hales Dept. of Anatomy & Cell Biology McGill University E-Mail: hales-at-hippo.medcor.mcgill.ca
Hi, there: One of my friends is going to buy a DVD writer. Does anybody know how much it costs and where to get information? Thanks in advance for your help. ------Weixin Xu------
A word to the wise. If you want people on a list to read your messages- don't send them as attachments- at least unless they are simple ASCII text files (but even that does not work for everyone). Attachments, often being specific to software, must be translated to be readable [this I know is a simplification]. Most of us won't take the time (or won't have the correct software) to accomplish the translation.
Jay Jerome ************************************************************** * aka: W. Gray Jerome * * Dept. of Pathology * * Bowman Gray School of Medicine of Wake Forest University * * Medical Center Blvd * * Winston-Salem, NC 27157-1092 * * 910-716-4972 * * jjerome-at-bgsm.edu * **************************************************************
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It is a bit more complex than you think. Apart from the "overall" situation the impinging electrons have momentum. they know electronsout of the surface layer, creating a positive volume and are deposited farther in. Truely immense field are thus created if the resistivity is high enough. Eventually breakdown occurs and the electrons trapped inside can actually blast out through the surface into the vacuum (ballistic electrons).
It is a can of worms and makes one realize that EPMA on insulators is an approximate activity at best. There was work on this in terms of looking at frozen biological specimens (ice being an insulator). If memory serves, the fellow involved was Ricke, in Germany about 20 years ago and he found that the electrons didn't penetrate anywhere near as far as they were supposed to because the internal field slowed them down. Note, this was on coated specimens!! They also didn't make as many x-rays as they should becuse much of their initial kinetic energy was still stored in the field of the "virtual capacitor" near the surface.
Jim Pawley
**************************************** Prof. James B. Pawley, Ph. 608-263-3147 Room 1235, Engineering Research Building, FAX 608-265-5315 1500 Engineering Dr., Madison, WI, 53706 JBPAWLEY-at-FACSTAFF.WISC.EDU
} } I've recently had an incident whereby I got EPMA analytical } } totals which were a bit high (101 to 103), and this went away when I } } was more liberal with the conductive paint.
Scott Walck added,
} I think the answer to your increased signal may lie in the cross section for } core ionization with overvoltage. If your sample charges negatively, then the } overvoltage will decrease. The cross section for ionization increases as the } overvoltage decreases. (It has a maximum at about 2.5-3.) Test this. When you } have a good sample that is behaving properly, reduce the beam voltage a little } and keep the probe current constant and see if the counts go up.
My own working definition for charging is that there is an avalanche of secondary electrons emitted from the sample. The practical effects of charging are that the electrons are slowed down going into the sample, because the negative local charge at the sample surface produces a force against the electrons arriving from the gun. The electrons may also be deflected away from the nominal beam spot. In terms of what you think you are analyzing, the beam may be on an adjacent grain, or on a grain boundary, etc. The beam could easily be deflected out of the lateral depth of field for the WDS spectrometers (several tens to hundreds of microns), the result being a lower x-ray intensity and therefore a low analytical total due to spectrometer defocusing.
Three ways to check for sample charging. First, the high energy cutoff of the EDS spectrum (Duane-Hunt limit) should ramp right up to the accelerating voltage. If it is routinely below that acc voltage, the sample is charging, and if it is above the acc voltage, you are seeing some pulse pileup -- that is ok. Secondly, if you are in imaging mode and you switch from very low mag right up to high mag, you may see a fairly rapid shift of the image due to beam deflection. Thirdly, you may see the absorbed current value jump around. Finally, for really bad charging, you see the streaking of the secondary electron image due to the SE avalanche. Of these it is my experience that the Duane-Hunt limit is most sensitive, and shows charging when none of these other features are observed. For this reason, you should acquire an EDS spectrum with each analysis to monitor the cutoff, as well as to check for missed elements.
The effect of electron retardation is to lower the overvoltage. This will reduce the generated x-ray intensity in the sample relative to the standard (assuming that the standard is fully conductive). If you are operating at an accelerating voltage that is 1.5 times the excitation energy of your most energetic line, then the ionization cross section is pretty linear in that range, and a small decrease in overvoltage should not really affect the cross section. Thus, a decrease in overvoltage (and intensity) will give you a low total, not a high one. If you are operating at a voltage that is right down on the excitation energy, then you are in the strongly curved portion of the cross section curve, and you might see an increase in intensity. But you should not be operating in this voltage regime to begin with, because we do not know the exact nature of the ionization cross section function. The same comment applies to a situation where, for example, the instrument is operating at 15KV but, due to charging, the sample is seeing an accelerating voltage more like 7 KV, i.e. really bad charging. This is what you would be talking about to really screw up a silicate analysis where Fe is your highest energy line.
Anyway, I don't really see why you should be getting high totals. You may wish to look beyond the topic of charging, like spectrometer alignment and reproducibility, standards, etc.
Paul
+----------------------------------------------------+ | Paul K. Carpenter paulc-at-gps.caltech.edu | | Division Analytical Facility | | Geological and Planetary Sciences MC 100-23 | | California Institute of Technology | | Pasadena, CA 91125 | | 818-395-6126 (X-ray Lab) 818-568-0935 (Dept. FAX) | +----------------------------------------------------+
I have a Polaron E5400 Sputter Coaterthat needs new gaskets. The gaskets I need go around the top and bottom of the glass sleeve(?). The thing that goes around the specimens and the sputtering thing sits on. Whatever... My old gaskets are getting cracked and that's probably causing it to take longer to pump down.
Does anyone out there know of a vendor on the West coast of the USA where I could buy my gaskets from?
Not only that, but what type of gasket do I need? Cuna? Viton? Neoprene? All I know is that it's black, rubber looking and kinda L shaped.
Thanks ahead of time for all the information.
Paula = ) The gasketless wonder. Electron Microscope Lab UC Berkeley
Thanks to Amanda Wilson, Bruce Wagner, and David Brauer for recommendations and comments. Bruce has recommended (pyro?) antimonate to precipitate Ca in place, localizing it, and I assume followed by TEM and electron probe to confirm the presence of Ca. I have heard of this technique, especially as applied to plants which employ sequestering of excess Ca as oxalate crystals in specialized cells called idioblasts. But I have also heard that your specimen must have very high levels of Ca present in some form, such as Ca crystals, in order for this method to work. So I also would assume that this method won't work for Ca which is held on the ion exchange groups of the cell wall, or as non-crystalline co-ions in the vacuole? Anyway, I will read up on the pyroantimonate method and see if it will track Ca even when it isn't a precipitate. Also will look at Alizarin red and try to translate to botanicals. Thanks, Janet.
Janet K. Dye Ph. D. Graduate Student, Soils Land, Air, and Water Resources University of California Davis, California USA (916) 752-0199 (916) 668-4217 jkdye-at-ucdavis.edu
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I wonder if anyone can help with this one?
I have a colleague who would like to embed a single cell after he has stimulated it with a fine carbon electrode which has been inserted into the cell. His eventual aim is to cut a section through the carbon electrode to see its intracellular orientation. However, to do this, he must keep the cell, with inserted electrode, in place on the microscope stage as he processes and embeds it - including resin polymerization.
This is the question:
Is there an EM embedding resin available that can be polylmerized without heating?
Could the regular Spuur or Epon mixes be modified by adding more DMP-30, or would that make the blocks too brittle to section?
The resins that polymerize under UV illumination would not work because we have no way of excluding oxygen from the resin surface.
If there is no good answer to this I suppose the next question should be: "what happens to an expensive light microscope after heating to 60#161#C for 8hr?"
Thanks in advance.
Paul Webster Center for Cell Imaging Yale School of Medicine http://info.med.yale.edu/cellimg
} It is a can of worms and makes one realize that EPMA on insulators is an } approximate activity at best. There was work on this in terms of looking } at frozen biological specimens (ice being an insulator). If memory serves, } the fellow involved was Ricke, in Germany about 20 years ago and he found } that the electrons didn't penetrate anywhere near as far as they were } supposed to because the internal field slowed them down. Note, this was on } coated specimens!! They also didn't make as many x-rays as they should } becuse much of their initial kinetic energy was still stored in the field } of the "virtual capacitor" near the surface. } } Jim Pawley
Do you have the reference for this? Or someone? Thanks! Phil
&&& Illigitimi non carborundum &&&&&&&& Philip Oshel Station A PO Box 5037 Champaign, IL 61825-5037 (217)244-3145 days (217)355-3145 evenings oshel-at-ux1.cso.uiuc.edu *** looking for a job again ******************
: Ritchie Sims asked, : : } } I've recently had an incident whereby I got EPMA analytical : } } totals which were a bit high (101 to 103), and this went away when I : } } was more liberal with the conductive paint.
and Paul K. Carpenter responded, : : The electrons may also be : deflected away from the nominal beam spot. In terms of what you think you : are analyzing, the beam may be on an adjacent grain, or on a grain : boundary, etc. The beam could easily be deflected out of the lateral depth : of field for the WDS spectrometers (several tens to hundreds of microns), : the result being a lower x-ray intensity and therefore a low analytical : total due to spectrometer defocusing. : : Anyway, I don't really see why you should be getting high totals. You may : wish to look beyond the topic of charging, like spectrometer alignment and : reproducibility, standards, etc. :
Beam deflection because of charging might even give high totals. I have seen beam line scans across a homogeneous sample have a maxima away from the zero deflection point. This occurred even when the spectrometer was "peaked" at the zero deflection point. Presumably this indicates some kind of spectrometer misalignment, but it could give high analytical totals.
Carl
Carl Henderson Electron Microbeam Analysis Laboratory University of Michigan 2005 C.C. Little Bldg. Ann Arbor, MI 48109-1063 USA -------------------------------- (313) 936-1550 (voice) (313) 763-4690 (FAX) chender-at-umich.edu (e-mail) --------------------------------
On 30 Jan 1997, Paul Webster wrote: } } I have a colleague who would like to embed a single cell after he has stimulated } it with a fine carbon electrode which has been inserted into the cell. His } eventual aim is to cut a section through the carbon electrode to see its } intracellular orientation. However, to do this, he must keep the cell, with } inserted electrode, in place on the microscope stage as he processes and embeds } it - including resin polymerization. } } This is the question: } } Is there an EM embedding resin available that can be polylmerized without } heating? }
Paul:
I have had reasonable success with a resin called Epo-Fix, sold by Electron Microscopy Sciences.
Weixin wrote; } } Hi, there: } One of my friends is going to buy a DVD writer. Does anybody know how } much it costs and where to get information? } Thanks in advance for your help.
We, Pioneer has demonstrated a prototype DVD-R at Japan Electronics Show last October. You can get some information from following WWWs. (Some of them are in Japanese with some pictures. Try your exploration!)
Dear Paul, There are several embedding resins that can be polymerized without heating, but I don't know about their sectioning capabitities. I use them to embed and polish bulk samples for SEM. They are Epokwik from Buehler, a two part epoxy that hardens in 0.5 hour and a cheaper alternative, called Jet-Set, that is made in Burnaby, B.C. These do heat themselves up a bit as they harden, but if you keep the volume low it shouldn't be too bad.
You wrote: } Is there an EM embedding resin available that can be polylmerized without } heating? } Regards, Mary Mary Mager Electron Microscopist Metals and Materials Eng., UBC 6350 Stores Rd. Vancouver, B.C. V6T 1Z4 CANADA tel:604-822-5648, fax:604-822-3619 e-mail: mager-at-unixg.ubc.ca
At last a technical question that doesn't sound like an extract from the parts list or instruction manual - how refreshing!
I can't help, though, unless you would like to come out here where I have a spare gasket and know somewhere to find more of these.
Date sent: Thu, 30 Jan 1997 14:39:26 -0800 (PST) To: microscopy-at-Sparc5.Microscopy.Com
Hey Kids!
I have a Polaron E5400 Sputter Coaterthat needs new gaskets. The gaskets I need go around the top and bottom of the glass sleeve(?). The thing that goes around the specimens and the sputtering thing sits on. Whatever... My old gaskets are getting cracked and that's probably causing it to take longer to pump down.
Does anyone out there know of a vendor on the West coast of the USA where I could buy my gaskets from?
Not only that, but what type of gasket do I need? Cuna? Viton? Neoprene? All I know is that it's black, rubber looking and kinda L shaped.
Thanks ahead of time for all the information.
Paula = ) The gasketless wonder. Electron Microscope Lab UC Berkeley
Robin H Cross Director : EM Unit, Rhodes University, Grahamstown, South Africa eurc-at-giraffe.ru.ac.za - tel: +27 461 318168 - fax: +27 461 24377
A Postdoctoral Research Assistant is required to provide analytical support for Geology Research using the SEM-EDX system. There may also be the opportunity to contribute to the undergraduate teaching programme if appropriate. The post will be tenable for a period of 13 months from 1st April 1997 to 30th April 1998. The post will commence on a salary of =A315,516 (point 3 on Researcher 'B' Scale). Application forms may be obtained from, and should be returned to, the Personnel Department, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford, OX3 0BP. The closing date for applications is 18th February 1997. Further details can be obtained from Dr R A Strachan (01865-483609 or e-mail rastrachan-at-brookes.ac.uk).
---------- } From: Paul Webster {paul.webster-at-Yale.edu} } } I have a colleague who would like to embed a single cell after he has stimulated } it with a fine carbon electrode which has been inserted into the cell. His } eventual aim is to cut a section through the carbon electrode to see its } intracellular orientation. However, to do this, he must keep the cell, with } inserted electrode, in place on the microscope stage as he processes and embeds } it - including resin polymerization. } } This is the question: } } Is there an EM embedding resin available that can be polylmerized without } heating? } } Could the regular Spuur or Epon mixes be modified by adding more DMP-30, or } would that make the blocks too brittle to section? } } The resins that polymerize under UV illumination would not work because we have } no way of excluding oxygen from the resin surface. } } If there is no good answer to this I suppose the next question should be: "what } happens to an expensive light microscope after heating to 60#161#C for 8hr?" ************************************** LR White with accelerator added cures at room temperature and below. LR Gold would cure at nasty minus temperatures. White intense light will do the curing. It's easy to keep out oxygen. Just set up a nitrogen cylinder with a two stage regulator and a tube outlet. Insert into the tube a pasteur pipette. Adjust the flow to give about a bubble a second with the pipette held in water. A cylinder at that flow rate will last many weeks. Use a retort clamp to fix the pipette within a few mm of the resin on the microscope slide. I expect that the light from the microscope itself - especially with a blue filter in place would cure the resin. With luck the nitrogen flow would also help to keep the specimen cool. I delightful experimental set-up to play with! I must mention that P&S sells LR White. I hope that this posting is of some help and I do not expect to sell a 44 gallon drum of the stuff to Paul Webster or anybody who is embedding single cells on slides. Cheers Jim Darley
Probing & Structure (Microscopy Supplies & Accessories) PO Box 111, Thuringowa QLD 4817 Australia
Phone +61 77 740 370 Fax: +61 77 892 313 A great microscopy site: http://www.ultra.net.au/~pns/
Although when you see the price, you may feel the gaskets are made from gold rather than rubber, many Polaron parts are available from Energy Beam Sciences, Inc., Agawam MA. The last # I have is (800) 992-9037.
Good Luk! Woody
My other address... woody.white-at-worldnet.att.net http://www.geocities.com/capecanaveral/3722
With a lower incident beam potential, the analysis volume (scatter) is smaller/more shallow. As the center analysis volume moves toward the material surface, resultant x-ray adsorption decreases. For the same energy input to the specimen, this can change not only countrates, but the overall shape of the acquired spectrum. This degree of effect is also a function of (at least) both the sample composition (softer x-rays are affected more than those of higher energy) and the beginning incident beam potential.
Woody
The other addresses... woody.white-at-worldnet.att.net http://www.geocities.com/capecanaveral/3722
{snip} core ionization with overvoltage. If your sample charges negatively, then the overvoltage will decrease. The cross section for ionization increases as the overvoltage decreases. (It has a maximum at about 2.5-3.) Test this. When you have a good sample that is behaving properly, reduce the beam voltage a little and keep the probe current constant and see if the counts go up. - -Scott Walck
Message-Id: {1.5.4.32.19970131141149.0069d310-at-biotech.ufl.edu} X-Sender: gwe-at-biotech.ufl.edu X-Mailer: Windows Eudora Light Version 1.5.4 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"
I believe that Unicryl (Biocryl) resin can be polymerized with UV in the presence of oxygen. It is sold by SPI. } } } } } } } } } } } } } } } } } } } } } } At 05:58 PM 1/30/97 -0500, you wrote: -----------------------------------------. } } } I wonder if anyone can help with this one? } } I have a colleague who would like to embed a single cell after he has stimulated } it with a fine carbon electrode which has been inserted into the cell. His } eventual aim is to cut a section through the carbon electrode to see its } intracellular orientation. However, to do this, he must keep the cell, with } inserted electrode, in place on the microscope stage as he processes and embeds } it - including resin polymerization. } } This is the question: } } Is there an EM embedding resin available that can be polylmerized without } heating? } } Could the regular Spuur or Epon mixes be modified by adding more DMP-30, or } would that make the blocks too brittle to section? } } The resins that polymerize under UV illumination would not work because we have } no way of excluding oxygen from the resin surface. } } If there is no good answer to this I suppose the next question should be: "what } happens to an expensive light microscope after heating to 60#161#C for 8hr?" } } Thanks in advance. } } Paul Webster } Center for Cell Imaging } Yale School of Medicine } http://info.med.yale.edu/cellimg } } } ******************************************************* G.W. Erdos, Ph.D. Phone: 352-392-1295 Scientific Director, ICBR Electron Microscopy Core Lab 218 Carr Hall Fax: 352-846-0251 University of Florida E-mail: gwe-at-biotech.ufl.edu Gainesville, FL 32611 http://www.biotech.ufl.edu/~emcl/ Home of the #1 Gators ***** "Many shall run to and fro, and knowledge shall be increased" Daniel 12:4
In answer to Paul Webster's question about polymerization in situ on a microscope stage. We routinely polymerize LR Gold with a halogen headlamp on a ringstand. the lamp is connected to a 12 volt battery charger and works well. If you used this in conjunction with Jim Darley's advise on excluding oxygen, you should/may not to much of a problem. We surround the sample as much as possible with aluminum foil to concentrate the light from the lamp on the specimen. Hank Adams EML New Mexico State University
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Hello All,
I am trying to get some opinions/data in regards to the relative accuracy of quantitative EDS vs. WDS. The specific case is the analysis of nickel in gold plating cross sections. The plating contains approximately 2.5% nickel (to improve mechanical properties), with no other elements present. The samples are polished mounts. The plating is over 4 microns thick, with a nickel underplate of 3 microns.
We stay away from the underplate region and with this thickness, I don't think there should be any interaction volume size problems.
We are using quantitative EDS with standards. The standards are plating coupons that have been analyzed by AA to have approximately 2.2 and 2.5% nickel. The beam current, mags, spot size etc are kept the same for each sample and analyze both standards before and after the sample. On the sample, we analyze 3 separate areas (500 sec acquires) and average the results.
Our results seem to be very good for this technique. On the standards, we are always within 0 to 0.2 percent of the standard (ie: 2.22% standard is between 2.1 to 2.3 %). On the samples, if we get a reading which is more than 0.2% different than the group, we will throw that data point out and acquire another for the average. If the post analysis standards do not get within the 0.2% tolerance, we will throw out all three data points and re-run the entire test.
For this particular application, will WDS provide better results, and if so, how much better? Also, why would it be better in this case where there is no deconvolution necessary.
With pure element standards, the results were not as good. It seems intuitive that this would be true, is there any reason why pure standards would give better results when you have standards that bracket the composition?
Thanks for any advice or data,
John Giles Senior Materials Engineer Honeywell Space Systems
I know it's hard to keep up with all of the mergers, new company names and so on in this field. The former Polaron (later, BioRad) range of specimen preparation equipment is now manufactured by VG Microtech, in England, again under the "Polaron" trade name.
For those of you in the United States, Energy Beam Sciences has been appointed the exclusive agent for VG Microtech, and we provide spare parts (like gaskets) and consumables (like targets), along with bench service, for this equipment, even obsolete models. For those of you in Canada, the same service is provided by Soquelec.
Best regards, Steven E. Slap, Vice-President ******************************** Energy Beam Sciences, Inc. Adding Brilliance To Your Vision ebs-at-ebsciences.com http://www.ebsciences.com/ ********************************
International Symposium on Geology and the Environment Istanbul, Turkey September 1 to 5, 1997
There will be a session on "Materials and Biomedical Applications of Laser Scanning and Tandem Scanning Reflected Light Confocal Microscopy" as part of the above mentioned symposium. The confocal session is scheduled for Thursday, September 4. The symposiom has been organized in celebration of the 50th anniversary of the Geological Congress of Turkey.
The confocal session is being organized by Kenneth C. Moore of the University of Iowa. For additional information on this session he can be contacted at kenneth-moore-at-uiowa.edu. General information on the symposium can be found at
Thomas Moninger (moninger-at-emiris.iaf.uiowa.edu) Central Microscopy Research Facility http://www.uiowa.edu/~cemrf 85 EMRB University of Iowa Iowa City, IA 52242 319-335-8142 FAX 319-335-8049
Is anyone in this group familiar with the philosophical debates about whether the things one sees in a microscope should be regarded as "real" (realism) or simply "useful" (instrumentalism)? Prominent philosophers of science interested in this are Ian Hacking, Bas van Fraassen, etc.
I would like to hear from anyone who has any interest in this area, whether they have heard of the debate before or not. It may some day play a role in teaching.
Alfred
----------------------------------------- Alfred Kracher Geological Sciences Iowa State University Ames, IA 50011-3212 akracher-at-iastate.edu http://www.public.iastate.edu/~akracher vox:515 294 5439 fax:515 294 6049 -----------------------------------------
I've been able to embed isolated cells in LR White between glass slides then polymerize with UV. I keep the slides together using those black spring clamps. To keep the cells from getting squashed I usually Super-glue some coverslips on the ends of one of the slides. The slides need to be treated with a mold-parting compound first so you can get them apart later. The LRW polymerizes well except for the outer edges.
I can provide more details if needed.
--Page Owen Connecticut College Dept. of Botany New London, CT
Dear Paul, Another choice for an embedding resin might be "Unicryl" - made by British BioCell (no - I have absolutely no connection). Although I haven't yet had experience with it I have heard good reports about it with regard to tissue morphology and antigenicity at the EM level. According to the booklet of information about it, it will polymerize anywhere between -50C and 60C - either by heat or UV. They maintain that at lower temperature (4C to -20C) evaporation is minimal and the blocks may not need to be covered. One of my colleagues reports that at -10C the blocks polymerized under UV while still exposed to the air (no cover at all).
Pat Hales Dept. of Anatomy & Cell Biology McGill University
} I've recently had an incident whereby I got EPMA analytical } totals which were a bit high (101 to 103), and this went away when I } was more liberal with the conductive paint.
A possible cause may be the reduced absorption of X-rays in your sample.
The negative charging inside your sample will reduce the penetration depth of the electrons, thus increasing the amount and the energy of SE and BSE electrons, and thus reducing the amount of electron-energy available for X-ray production. So in combination with the lower effective penetration voltage percentages of less than 100 are usually expected.
But if your sample contains elements that emit X-rays that are heavily absorbed in the compound (esp. ultra-light elements) then the reduction of the amount of X-rays generated could be more than compensated by the fact that those X-ray that are still produced get to the surface much more easily, increasing the emitted X-ray intensity.
For further reading: Please see the article from Bastin and Heijligers in "Electron Probe Quantitation" (Ed. Heinrich & Newbury, Plenum 1991, pages 163-175), in which the EPMA of non-conductive specimens is discussed.
Hans Dijkstra
EDAX International European support office Tilburg, the Netherlands hans.dijkstra-at-edax.nl
} } It is a can of worms and makes one realize that EPMA on insulators is an } } approximate activity at best. There was work on this in terms of looking } } at frozen biological specimens (ice being an insulator). If memory serves, } } the fellow involved was Ricke, in Germany about 20 years ago and he found } } that the electrons didn't penetrate anywhere near as far as they were } } supposed to because the internal field slowed them down. Note, this was on } } coated specimens!! They also didn't make as many x-rays as they should } } becuse much of their initial kinetic energy was still stored in the field } } of the "virtual capacitor" near the surface. } } } } Jim Pawley } } Do you have the reference for this? Or someone? Thanks! } Phil
Here you go Phil and others.
Nothing on the Gernam group but the name Dorge comes to mind. Otherwise it is:
Pawley, J.B. (1972) Charging artifacts in the scanning electron microscope. Scanning Electron Microsc. 1972 (I), 153-160
Shaffner, T.H., Hearle, J.W.S. (1976) Recent advances in understanding specimen charging. Scanning Electron Microsc. 1976 (I), 61-70
**************************************** Prof. James B. Pawley, Ph. 608-263-3147 Room 1235, Engineering Research Building, FAX 608-265-5315 1500 Engineering Dr., Madison, WI, 53706 JBPAWLEY-at-FACSTAFF.WISC.EDU
} Bruce has recommended (pyro?) antimonate to precipitate Ca in place,
Yes, pyroantimonate. This can, however, wreck havoc with the ultrastructure; try it and see.
} localizing it, and I assume followed by TEM and electron probe to confirm } the presence of Ca.
You can also locate the antimony by EDS.
} I have heard of this technique, especially as applied } to plants which employ sequestering of excess Ca as oxalate crystals in } specialized cells called idioblasts.
If you have ~ micron-sized CaC2O4 xtals, you can use EDS directly without using pyroantimonate--there is plenty of Ca in them.
} But I have also heard that your } specimen must have very high levels of Ca present in some form, such as Ca } crystals, in order for this method to work. So I also would assume that } this method won't work for Ca which is held on the ion exchange groups of } the cell wall, or as non-crystalline co-ions in the vacuole?
EDS needs a large fraction of a %, or ~mM concentrations (wet) to detect and quantitate an element. It is irrelevant what the chemical form of the element is. These amounts must only be present in the analysed volume; the overall amount can be very much less as long as it is present in small, concentrated regions.
} Anyway, I will read up on the pyroantimonate method and see if it will } track Ca even when it isn't a precipitate.
Any Ca++, and other Ca which has a greater affinity for pyroan- timonate than for its ligands will be precipitated. Good luck. Yours, Bill Tivol
oThe displacement of the idea that facts and evidence matter by the idea that everything boils down to subjective interests and perspectives is -- second only to American political campaigns -- the most prominent and pernicious manifestation of anti-intellectualism in our time.
-- Larry Laudan, Science and Relativism(1990), Quoted by Alan Sokal in article 2, below.
I refer those considering this question seriously to read the articles: 1. "Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity " by Alan D. Sokal (published in Social Text)46/47, pp. 217-252 (spring/summer 1996).
-and the follow-up article:
2. "A Physicist Experiments With Cultural Studies"
also by Alan D. Sokal published in Lingua Franca, May/June 1996, pp. 62-64.
--------------------------------------
This may sound really bizarre to some of, but...
Is anyone in this group familiar with the philosophical debates about whether the things one sees in a microscope should be regarded as "real" (realism) or simply "useful" (instrumentalism)? Prominent philosophers of science interested in this are Ian Hacking, Bas van Fraassen, etc.
I would like to hear from anyone who has any interest in this area, whether they have heard of the debate before or not. It may some day play a role in teaching.
Alfred
----------------------------------------- Alfred Kracher Geological Sciences Iowa State University Ames, IA 50011-3212 akracher-at-iastate.edu http://www.public.iastate.edu/~akracher vox:515 294 5439 fax:515 294 6049 -----------------------------------------
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At 05:58 PM 1/30/97 -0500, you wrote: -----------------------------------------. } I wonder if anyone can help with this one? } } I have a colleague who would like to embed a single cell after he has } stimulated } it with a fine carbon electrode which has been inserted into the cell. His } eventual aim is to cut a section through the carbon electrode to see its } intracellular orientation. However, to do this, he must keep the cell, with } inserted electrode, in place on the microscope stage as he processes and } embeds } it - including resin polymerization. } } This is the question: } } Is there an EM embedding resin available that can be polylmerized without } heating?
Paul - You don't say what resolution your friend requires. Would it be possible to do this on the stage of a confocal scope, thus eliminating embedding & sectioning? As a group, the UV-polymerizing resins have miserable cutting characteristics, and I presume that the electrode is a lot harder than the cell. Sectioning this prep will not be easy.
Caroline Schooley Educational Outreach Coordinator Microscopy Society of America Box 117 Caspar, CA 95420
On Sat, 1 Feb 1997 22:50:32 -0600 (cst) Doug Keene {DRK-at-shcc.org} wrote:
} } Responding to a query of a few days ago, we routinely cut } bone and growth plate in this facility. Our processing } routine includes fixation in 1.5% glut / 1.5% } paraformaldehyde in 0.1 M cacodylate pH 7.4 containing } 6,000 ppm ruthenium hexamine trichloride (fix for 60 } minutes) followed by o.1m cacodylate with 6,000ppm RHT for } 15 minutes, followed by 1% OsO4 in the same buffer with } RHT. The buffer rinse after OsO4 should be 0.1M cacodylate } with no RHT. This is a somewhat modified } procedure of Hunziker et al., J Ultrastruct Res 8:1, 1984. } Dehydrate in 30, 50, 70, 90, 95 % EtOH, Propylene oxide, } infiltrate in Spurrs and polymerize at 70 C for 16 hours. } We face the block and section for LM using a glass knife, } then use a somewhat damaged area of our diamond for } ultrathin sections. We always have two diamond knives } open in the lab, one which is slowly getting trashed } cutting relatively soft tissue and one which is no longer } optimal and is now used to cut calcified samples. The } lifetime of the knives is usually about 7 to 8 months } before resharpening. Our blocks are often larger than 0.5 } x 1 mm. } } Hope this helps, } } Doug Keene } Shriners Hospital for Children } Portland (always raining) Oregon } ---------------------- } Doug Keene } DRK-at-shcc.org }
At 11:17 AM 1/31/97 -0500, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
} For this particular application, will WDS provide better results, and if so, } how much better? Also, why would it be better in this case where there is no } deconvolution necessary.
John ...
It bothers me sometimes when EDX is compared with WDX, the accuracy for EDX is evaluated relative to having measured a known ... and claiming the result is "good", "excellent", or for that matter "close enuf" ...
My definitition of "quantitative analysis" also includes quantifying the error associated with the analysis. WDX makes this easy ... pure counting stats with regard to the integral and that associated with subtracting the background. It is the statistical evaluation of the background subtraction (let alone the error probagated by de-convoluting) which make evaluation of the counting error almost impossible with EDX.
It is true, that with today's computing power, the analyst wouldn't have to wait very long for an error associated with "modelling" the EDX continuum, but I don't see any EDX vendors delivering this error analysis. It is also true, the error associated with de-convolution, as common as it is needed, is also just as important. I'd certainly be interested in reading others' opinion on applying error analysis to the continuum, and subsequent determination of EDX sensitivities and detection limits.
So, my answer to your question, is there is no comparison ... if you want quantitation with accurate error analysis ... EDX is ^not^ your tool. However, I'm not saying it is inappropriate for Ni in Au at those compositions ... you don't appear to be near any detection limits. But, I would be careful with reporting your accuracies ...
cheers, shAf
{\/} /\ {\/} /\ {\/} /\ {\/} cogito, ergo ZOooOM {\/} /\ {\/} /\ {\/} /\ {\/} Michael Shaffer, R.A. - University of Oregon Electron Probe Facility mshaf-at-oregon.uoregon.edu -or- mshaf-at-darkwing.uoregon.edu http://darkwing.uoregon.edu/~mshaf/
Responding to a query of a few days ago, we routinely cut bone and growth plate in this facility. Our processing routine includes fixation in 1.5% glut / 1.5% paraformaldehyde in 0.1 M cacodylate pH 7.4 containing 6,000 ppm ruthenium hexamine trichloride (fix for 60 minutes) followed by o.1m cacodylate with 6,000ppm RHT for 15 minutes, followed by 1% OsO4 in the same buffer with RHT. The buffer rinse after OsO4 should be 0.1M cacodylate with no RHT. This is a somewhat modified procedure of Hunziker et al., J Ultrastruct Res 8:1, 1984. Dehydrate in 30, 50, 70, 90, 95 % EtOH, Propylene oxide, infiltrate in Spurrs and polymerize at 70 C for 16 hours. We face the block and section for LM using a glass knife, then use a somewhat damaged area of our diamond for ultrathin sections. We always have two diamond knives open in the lab, one which is slowly getting trashed cutting relatively soft tissue and one which is no longer optimal and is now used to cut calcified samples. The lifetime of the knives is usually about 7 to 8 months before resharpening. Our blocks are often larger than 0.5 x 1 mm.
Hope this helps,
Doug Keene Shriners Hospital for Children Portland (always raining) Oregon ---------------------- Doug Keene DRK-at-shcc.org
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