Electron Microscopy Laboratory Research Articles

An examination of a strand of 30,000 and 70,000 year old mammoth hair

The Scanning Electron Microscopy Laboratory has received two strands of hair from a Mammoth. These strands were obtained from the Smithsonian Institution in Washington D.C. One 70,000 year old strand from North Yakutia which was a part of the former USSR, is a clear smooth yellowish strand. While, the other strand which is approximately 30,000 years old, under the Electron microscope seems to have a rough surface. This strand is from Muck, Alaska. The 70,000 year old strand from USSR has unusual scratches, but in comparison with human hair of today it seems to display some of the tree bark growth phenomenon observed in human hair. The 30,000 year old strand of hair seem to have unusual rocky structures attached to shaft with large pits and channels. X ray analysis of the 70,000 year old Russian strand seem to indicate large deposits of calcium, iron, copper, and sulfur. Further, the 30,000 year old strand shows copper, iron, calcium and potassium with large quantities of silicon and fluorine.

Diagnostic electron microscopy: future development.

When the electron microscope was initially developed, pathologists thought that it would become the ultimate diagnostic tool for tumor diagnosis because the structure of subcellular organelles could be visualized. However, the role of diagnostic electron microscopy in tumor diagnosis diminished rapidly when it was noted that there were a finite number of diagnostic subcellular organelles and that immunohistochemistry could yield the answer to questions which related to tumor diagnosis more rapidly and cheaply. If diagnostic EM is to remain a viable entity, its future role in tumor diagnosis lies in exploiting the relevance of the correlation between structure and function of subcellular organelles. This correlation between structure and function of subcellular organelles is best accomplished in an environment in which the recent technologic advances in electronics are incorporated into the electron microscopy laboratory.

Microcomputer application: an image database system for electron microscopy.

An electron microscopist in a small electron microscopy laboratory that processes 200 cases per year can generate at least 2000 electron micrographs within this time period. These electron micrographs are stored in filing cabinets, which slowly encroach on existing laboratory space. Related image data are often located in separate filing systems. This type of storage system is inefficient for rapid retrieval of sets of electron micrographs for research, teaching, or retrospective review of patient material. An electron microscopy image base, which is implemented on a microcomputer, can provide flexible and simultaneous access to both digitized electron micrographs and their relevant textual data. In addition to the advantage of more efficient retrieval, electronic storage of textual data and digitized electron micrographs also offers the advantage of decreased storage space for this type of data. Implementation of the initial version of the electron microscopy image base demonstrated that future versions must provide improved resolution of the digitized electron micrograph and sufficient electronic mass storage to support such a large image base. Ongoing developments in database technology and mass storage make it worthwhile to pursue additional refinements of the electron microscopy image base.

Colloidal gold labeling of sections and cell surfaces.

Colloidal gold labeling techniques can be simplified enough to become practical for diagnostic use in a hospital electron microscopy laboratory. Methods found to be practical and reproducible are presented, including production of colloidal gold reagents, polar embedding for gold labeling of thin sections, and use of silver enhancement on semithin sections. Methods for cell surface labeling are emphasized; they are technically straightforward and can be applied to investigation of multiple diagnostic problems.

An Eperyhbvzwn-Like Parasite of Llamas: Attempted Transmission to Swine, Sheep, and Cats

appear and noted a few early reports where pseudospirochetes were erroneously implicated as causes for diseases. With current interest in Lyme borreliosis, some veterinary diagnosticians may be asked to perform darkfield microscopy on specimens. Diagnosticians should be alert to this potential source of diagnostic error. Acknowledgments. We thank Laura Cullins and the electron microscopy laboratory at the College of Veterinary Medicine, North Carolina State University, and Walton Steffens and Mary Ard from the electron microscopy laboratory at the College of Veterinary Medicine, University of Georgia, for their assistance.

Preparation of radial hair sections for element profile measurements with a proton microprobe

A new technique has been developed to prepare radial hair sections for element profile analysis using a proton microprobe (PM). The technique makes use of equipment and supplies standard in histological electron microscopy laboratories. In addition to obtaining radial hair slices, adjacent 1 μm thick slices can be acquired for comparative light microscope viewing. With these adjacent optical slices, element profiles of transitional phase and irregularly shaped hair are easily studied. Selected radial sections of C57L/J mouse hair, used to represent this technique, showed element distribution profiles largely similar to their histological counterpart in human hair.

Personal‐computer‐based system for electron beam X‐ray microanalysis of biological samples

A system based on a personal computer has been developed which provides a relatively inexpensive way to equip an electron microscopy laboratory for quantitative elemental analyses of cryosectioned biological samples. This system demonstrates the feasibility of making an X-ray analyser from a personal computer, together with commercially available hardware and software components. Hardware and software have been assembled to drive the beam in a scanning electron microscope, collect and analyse X-ray spectra, and save, retrieve, and analyse data. Our software provides a menu-controlled user interface to direct spectra acquisition and analysis. Spot analyses, video images, and quantitative elemental images may be obtained and results transferred in ASCII format to other computers. Wet weight, as well as dry weight, concentrations are calculated, if measurements were made of areas of the hydrated sample before it was freeze-dried. Grey-level copies of video and quantitative elemental images may be made on a laser printer.

X-ray standing-wave technique in the study of impurity location in the crystal lattice near the surface

In this paper the principle of the X-ray standing-wave (XSW) method which is a new precise and sensitive technique of determination of atomic positions inside crystals or at their surfaces is described. The construction of a double crystal diffractometer in the X-ray and Electron Microscopy Laboratory of the Institute of Physics of the Polish Academy of Sciences in Warsaw is also reported. Some examples of the application of this technique are given. As reported by Funke et al. [Nucl. Instrum. Methods A 246 (1986) 763] the experiment can also be performed in ultra-high vacuum.

An overview of North American user facilities for electron microscopy in the physical sciences

Physical scientists working in North America have access to five major User Facilities for advanced applications of electron microscopy. These Facilities are distributed geographically as shown in Figure 1, and provide a wide range of sophisticated instrumentation not normally found in the conventional electron microscope laboratory. Born of the need to maintain state-of- the-art equipment for research in the physical sciences and created because of the increasing cost and sophistication of such instrumentation, they operate on a “shareable” basis, having been funded by the government agencies to serve as regional and national resources, not for exclusive parochial access.The five facilities described here are: [1] the National Center for Electron Microscopy at the Lawrence Berkeley Laboratory, funded by the Department of Energy; [2] the Facility for High Resolution Electron Microscopy at Arizona State University, funded by the National Science Foundation; [3] the Center for Microanalysis of Materials at the University of Illinois, Urbana-Champaign, funded by both the Department of Energy and the National Science Foundation;

Electron microscopy in the community hospital

A common misconception exists that a diagnostic electron microscopy laboratory can not succeed fiscally in a community hospital. This has not been the case in our institution. An electron microscopy laboratory was established in 1982 and the initial investment by the hospital was recovered within four years. Billings have remained relatively constant during the past several years. In addition to financial considerations, the laboratory has been beneficial diagnostically, allowing for rapid, easy access to this valuable tool. In fact, the presence of an electron microscope in the hospital has probably encouraged further utilization of this technology. The electron microscopy laboratory has also been an asset in our teaching program, not only for the demonstration of the ultrastructural findings themselves, but also for the consultative material sent from other institutions. Finally, the laboratory has opened up research possibilities not otherwise available.

Simulation and information assessment of TEM and STEM images

Small and moderate digital systems, especially those with computer-microscope interface capabilities and possibly equipped with image frame stores, are being commonly employed in electron microscopy laboratories. The complexity of such systems varies greatly, ranging from those composed of simply a personal computer with minimum interfacing hardwares such as digital to analog converters(DACs) and pulse counters (or ADCs), compact enough to be fitted into a small cart and transported from room to room, to those consisting of image processing systems controlled by mini- or super mini-computers with system-bus interface for massive data transfer, array processors for fast online data handling. Be it simple or complex, such a system allows signals from various sources to be collected and stored in digital form for on-line or off-line manipulation. Fig.1 is a highly schematic diagram of the system currently working in ASU HREM laboratory, on which this work was done.

Integrated microscopy resource for biomedical research at the university of wisconsin at madison

The High Voltage Electron Microscopy Laboratory [HVEM] at the University of Wisconsin-Madison, a National Institutes of Health Biomedical Research Technology Resource, has recently been renamed the Integrated Microscopy Resource for Biomedical Research [IMR]. This change is designed to highlight both our increasing abilities to provide sophisticated microscopes for biomedical investigators, and the expansion of our mission beyond furnishing access to a million-volt transmission electron microscope. This abstract will describe the current status of the IMR, some preliminary results, our upcoming plans, and the current procedures for applying for microscope time.The IMR has five principal facilities:1.High Voltage Electron Microscopy2.Computer-Based Motion Analysis3.Low Voltage High-Resolution Scanning Electron Microscopy4.Tandem Scanning Reflected Light Microscopy5.Computer-Enhanced Video MicroscopyThe IMR houses an AEI-EM7 one million-volt transmission electron microscope.

Plant Pathology Diagnosed by X-Ray Microanalysis

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.

Scanning Electron Microscopy of the Palp Sense Organs of the Harvestman Leiobunum townsendi (Arachnida: Opiliones)

Scanning Electron Microscopy of the Palp Sense Organs of the Harvestman Leiobunum townsendi (Arachnida: Opiliones)

Pseudo-weak-phase-object approximation in high-resolution electron microscopy. II. Feasibility of directly observing Li+

Abstract Images of Li2Ti307 were calculated with the multislice method and observed with a JEM-200CX electron microscope. Both calculated and observed images show that Li ÷ ions can be seen intuitively under an optimum imaging condition as is predicted by the theory of the pseudo-weak-phase-object approxi- mation. 1. Introduction In the earlier papers in this study (Li & Tang, 1984, 1985) the dependence of image contrast on crystal thickness was discussed. When the crystal is too thick to allow the weak-phase-object approximation (WPOA) to hold, it was shown that with increasing crystal thickness the image contrast of light atoms increases more rapidly than that of heavy atoms. Hence, crystals too thick for weak-phase-object approximation to hold but thinner than the critical thickness have been treated as pseudo-weak phase objects. Under the optimum imaging condition the image intensity can be expressed as I(r)= 1- 2o'~o'(r). (1) Here ~o'(r) is the modified projected potential distri- bution function (PPDF) which can be treated as the PPDF of an imaginary isomorph of the examined crystal where real atoms are replaced by imaginary ones. The constituent heavy and light atoms of the imaginary isomorph are respectively lighter and heavier than those of the real crystal. This indicates the possibility of preferentially revealing different kinds of atoms by choosing observation regions of different thicknesses in the crystal examined. It was found by the HREM (high-resolution elec- tron microscopy) observation on the mineral cebaite BasCe2(CO3)sFz that within a certain range of crystal thicknesses the image contrast is sensitive to the posi- tions of light atoms (C, O, F) and hence the positions of these light atoms were determined by HREM (Li * Projects supported by the Science Fund of the Chinese Academy of Sciences. t Present address: Beijing Electron Microscope Laboratory, PO Box 2724, Beijing, China.

Technical Evaluation of Four Common Embedding Resins Used in Electron Microscopy

Today, numerous types of embedding media are available for use in the electron microscopy laboratory. Laboratories generally choose a particular embedding media based on their own practical experiences with it. This study was performed to compare and evaluate four common resins found in electron microscopy laboratories.Skeletal muscle was removed from rats perfused with 3% glutaraldehyde in 0.1M collidine, cut into rectangles and allowed to remain in fixative for 6 hours. Tissue was then washed in 0.1M collidine buffer and post fixed for 1 hour with 1% osmium tetroxide in 0.1M collidine. After rinsing in collidine buffer the tissue was divided into groups for processing according to established procedures for the following resins: Araldite, Epon, Mollenhauer, Spurr (see formulas).

Techniques with resins other than glycol methacrylate

At present, resin formulas other than the widely used Epon 812 mixtures are being successfully employed in electron microscopy laboratories at Michigan State University. The purpose of this presentation is to share information concerning materials and methods used in various electron microscopy laboratories at M.S.U.

Safety in the scanning electron microscope laboratory

ScanningVolume 7, Issue 5 p. 255-272 Original PaperFree to Read Safety in the scanning electron microscope laboratory J. Bastacky, J. Bastacky Donner Laboratory, Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720, USASearch for more papers by this authorT. L. Hayes, T. L. Hayes Donner Laboratory, Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720, USASearch for more papers by this author J. Bastacky, J. Bastacky Donner Laboratory, Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720, USASearch for more papers by this authorT. L. Hayes, T. L. Hayes Donner Laboratory, Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720, USASearch for more papers by this author First published: 1985 https://doi.org/10.1002/sca.4950070506Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume7, Issue51985Pages 255-272 RelatedInformation

Cautions, common sense, and rationale for the electron microscopy laboratory

AbstractThis paper is a condensation of precautions, general information, and common‐sense tips designed to assist students in electron microscopy. Although not all circumstances are included and many of the recommendations are common sense, this handout has proven invaluable to beginners in two different multiuser electron microscopy facilities. When integrated by discussion and testing into the initial training period, this information will save the neophyte, lab manager, and others working in a multiuser facility untold hours of frustration, of wasted time, effort, and supplies, and of exposure to the myriad environmental hazards inherent in the performance of electron microscopy. The rationale for these suggestions is included, enhancing problem‐solving in situations not covered directly in this presentation.

Aminoplastic-standards for quantitative X-ray microanalysis: N. Roos and T. Barnard, Electron Microscopy Laboratory for Bioscience, Postbox 1062, University of Oslo, Blindern, N 0136 Oslo 3, Norway

Aminoplastic-standards for quantitative X-ray microanalysis: N. Roos and T. Barnard, Electron Microscopy Laboratory for Bioscience, Postbox 1062, University of Oslo, Blindern, N 0136 Oslo 3, Norway