scholarly journals Diagnostic Electron Microscopy of Viruses With Low-voltage Electron Microscopes

2020 ◽  
Vol 68 (6) ◽  
pp. 389-402
Author(s):  
Lars Möller ◽  
Gudrun Holland ◽  
Michael Laue
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Voltage ◽  
Low Voltage ◽  
Optical Resolution ◽  
Plant Diseases ◽  
Voltage Electron ◽  
Transmission Electron ◽  
High Voltage Transmission ◽  
Electron Microscopes

Diagnostic electron microscopy is a useful technique for the identification of viruses associated with human, animal, or plant diseases. The size of virus structures requires a high optical resolution (i.e., about 1 nm), which, for a long time, was only provided by transmission electron microscopes operated at 60 kV and above. During the last decade, low-voltage electron microscopy has been improved and potentially provides an alternative to the use of high-voltage electron microscopy for diagnostic electron microscopy of viruses. Therefore, we have compared the imaging capabilities of three low-voltage electron microscopes, a scanning electron microscope equipped with a scanning transmission detector and two low-voltage transmission electron microscopes, operated at 25 kV, with the imaging capabilities of a high-voltage transmission electron microscope using different viruses in samples prepared by negative staining and ultrathin sectioning. All of the microscopes provided sufficient optical resolution for a recognition of the viruses tested. In ultrathin sections, ultrastructural details of virus genesis could be revealed. Speed of imaging was fast enough to allow rapid screening of diagnostic samples at a reasonable throughput. In summary, the results suggest that low-voltage microscopes are a suitable alternative to high-voltage transmission electron microscopes for diagnostic electron microscopy of viruses.

Remote On-Line Control of a High-Voltage in situ Transmission Electron Microscope with A Rational User Interface

1996 ◽  
Vol 54 ◽  
pp. 384-385
Author(s):  
M.A. O’Keefe ◽  
J. Taylor ◽  
D. Owen ◽  
B. Crowley ◽  
K.H. Westmacott ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
User Interface ◽  
Transmission Electron Microscope ◽  
High Voltage ◽  
Materials Science ◽  
Transmission Electron ◽  
On Line ◽  
Electron Microscopes

Remote on-line electron microscopy is rapidly becoming more available as improvements continue to be developed in the software and hardware of interfaces and networks. Scanning electron microscopes have been driven remotely across both wide and local area networks. Initial implementations with transmission electron microscopes have targeted unique facilities like an advanced analytical electron microscope, a biological 3-D IVEM and a HVEM capable of in situ materials science applications. As implementations of on-line transmission electron microscopy become more widespread, it is essential that suitable standards be developed and followed. Two such standards have been proposed for a high-level protocol language for on-line access, and we have proposed a rational graphical user interface. The user interface we present here is based on experience gained with a full-function materials science application providing users of the National Center for Electron Microscopy with remote on-line access to a 1.5MeV Kratos EM-1500 in situ high-voltage transmission electron microscope via existing wide area networks. We have developed and implemented, and are continuing to refine, a set of tools, protocols, and interfaces to run the Kratos EM-1500 on-line for collaborative research. Computer tools for capturing and manipulating real-time video signals are integrated into a standardized user interface that may be used for remote access to any transmission electron microscope equipped with a suitable control computer.

High Voltage Electron Microscopy in Biology

1970 ◽  
Vol 28 ◽  
pp. 12-13
Author(s):  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Electron Microscope ◽  
High Voltage ◽  
Cell Structure ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Sectioning Method ◽  
High Voltage Electron ◽  
Electron Microscopes

Conventional electron microscopes operate with accelerating voltages up to 100kV. Because of the scattering of electrons by atoms of the specimen an image with reasonable resolution can only be obtained with very thin specimens. The study of cell structure with the electron microscope became possible only with the introduction of ultramicrotomes which produce sections of plastic-embedded tissues down to about 100A in thickness. It has long been known that useful images could be obtained with much thicker materials at higher accelerating voltages (cf. refs. 1 and 2) and in the early sixties electron microscopes operating at voltages of up to one million Volts were built in Japan and in France. Their capabilities were soon demonstrated in metallurgy but they were ignored until recently by biologists. For one, biologists were busy exploiting the sectioning method and in addition may have been deterred by the knowledge that scattering contrast rapidly decreases at higher accelerating voltage. Only recently has it been realized that excellent contrast is obtained at 500 and 1000kV with the usual heavy metal stains (3,4). High voltage microscopes are now manufactured commercially in England (AEI), France (GESPA) and Japan (Hitachi, Jeol) and should soon be more widely accessible.

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

1987 ◽  
Vol 45 ◽  
pp. 594-597 ◽  
Author(s):  
G. Schatten ◽  
J. Pawley ◽  
H. Ris
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
High Voltage ◽  
Biomedical Research ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
Transmission Electron ◽  
The University

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.

Development of Field Emission Gun for High Voltage Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 604-605
Author(s):  
H. Shimoyama ◽  
C. Morita ◽  
S. Arai ◽  
N. Yokoi ◽  
K. Miyauchi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Field Emission ◽  
High Voltage ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Transmission Electron ◽  
Scanning Transmission

For the last few years we have been developing a field emission (FE) gun system for our high voltage electron microscope (HVEM) H-1250 ST (maximum accelerating voltage of 1.25 MV) at Nagoya University, in order to attain much higher level of performance of the instrument and to exploit further extended field of application. In the first stage of the project during the period from 1986 to 1987, the FE gun system had been mounted on the top of the accelerating tube, and successfully been operated at the accelerating voltage of 1 MV for the first time pin the world. The operation was very stable and high resolution images for both scanning transmission electron microscopy (STEM) and conventional transmission electron microscopy (CTEM) modes were possible at this stage. At the same time, however, several practical problems related to incorporating the FE gun into the HVEM were made clear. Since then several important modifications on instrumentation and electronics have been made and the project is now at the second stage. In this paper a brief outline of the FE gun system developed for our HVEM is described especially from the view point of instrumentation and electronics.

scholarly journals High Voltage Microscopy in Paleontological Studies – Graptolites

1970 ◽  
Vol 28 ◽  
pp. 492-493
Author(s):  
W. B. N. Berry ◽  
R. S. Takagi ◽  
G. Thomas ◽  
D. J. Jurica
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
The Other ◽  
Transmission Power ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Thin Sectioning ◽  
Electron Microscopes ◽  
Biological Methods

Transmission electron microscopy has seldom been used in studies of fossils, and to date, no electron diffraction work has been reported. Because of the limited transmission power of the 100 kV electron microscopes (<lμ), the techniques which have been used to prepare specimens have followed standard biological methods, including ultra-thin sectioning and staining. High voltage electron microscopy on the other hand allows examination of considerably thicker specimens (up to 5μ at 500 kV) and is particularly useful in studying fossils e.g. it is often not necessary to section pieces of the fossil. Minimal preparation is advantageous because materials that have been interred in rocks of the earth's crust for millions of years are commonly brittle and distort or break while being sectioned with the microtome.

scholarly journals Optimizing parameters for correlative immunogold localization by video-enhanced light microscopy, high-voltage transmission electron microscopy, and field emission scanning electron microscopy.

1990 ◽  
Vol 38 (12) ◽  
pp. 1781-1785 ◽  
Author(s):  
S R Simmons ◽  
J B Pawley ◽  
R M Albrecht
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
High Voltage ◽  
Low Voltage ◽  
Immunogold Localization ◽  
Transmission Electron ◽  
High Voltage Transmission ◽  
Scanning Electron

Correlative video-enhanced light microscopy, high-voltage transmission electron microscopy, and low-voltage high resolution scanning electron microscopy were used to examine the binding of colloidal gold-labeled fibrinogen to platelet surfaces. Optimal conditions for the detection of large (18 nm) and small (3 nm) gold particles are described.

The Reduction of Chromatic Aberrations Due to Instrumental Instabilities

1971 ◽  
Vol 29 ◽  
pp. 14-15
Author(s):  
J. S. Lally ◽  
R. Evans
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Usual Practice ◽  
Voltage Electron ◽  
Short Focal Length ◽  
Chromatic Aberrations ◽  
Electron Microscopes

One of the instrumental factors often limiting the resolution of the electron microscope is image defocussing due to changes in accelerating voltage or objective lens current. This factor is particularly important in high voltage electron microscopes both because of the higher voltages and lens currents required but also because of the inherently longer focal lengths, i.e. 6 mm in contrast to 1.5-2.2 mm for modern short focal length objectives.The usual practice in commercial electron microscopes is to design separately stabilized accelerating voltage and lens supplies. In this case chromatic aberration in the image is caused by the random and independent fluctuations of both the high voltage and objective lens current.

The Network Parameters Of The T-System In Frog Muscle Measured With The High Voltage Electron Microscope.

1975 ◽  
Vol 33 ◽  
pp. 550-551 ◽  
Author(s):  
Brenda R. Eisenberg ◽  
Lee D. Peachey
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Voltage ◽  
Sartorius Muscle ◽  
High Voltage Electron Microscopy ◽  
Network Parameters ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
T System

Analysis of the electrical properties of the t-system requires knowledge of the geometry of the t-system network. It is now possible to determine the network parameters experimentally by use of high voltage electron microscopy. The t-system was marked with exogenous peroxidase. Conventional methods of electron microscopy were used to fix and embed the sartorius muscle from four frogs. Transverse slices 0.5-1.0 μm thick were viewed at an accelerating voltage of 1000 kV using the JEM-1000 high voltage electron microscope at Boulder, Colorado and prints at x5000 were used for analysis.The length of a t-branch (t) from node to node (Fig. 1a) was measured with a magnifier; at least 150 t-branches around 30 myofibrils were measured from each frog. The mean length of t is 0.90 ± 0.11 μm and the number of branches per myofibril is 5.4 ± 0.2 (mean ± SD, n = 4 frogs).

Current and future aberration correctors for the improvement of resolution in electron microscopy

2009 ◽  
Vol 367 (1903) ◽  
pp. 3665-3682 ◽  
Author(s):  
M. Haider ◽  
P. Hartel ◽  
H. Müller ◽  
S. Uhlemann ◽  
J. Zach
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Spherical Aberration ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Voltage Electron ◽  
System A ◽  
Transmission Electron ◽  
Correction System

The achievable resolution of a modern transmission electron microscope (TEM) is mainly limited by the inherent aberrations of the objective lens. Hence, one major goal over the past decade has been the development of aberration correctors to compensate the spherical aberration. Such a correction system is now available and it is possible to improve the resolution with this corrector. When high resolution in a TEM is required, one important parameter, the field of view, also has to be considered. In addition, especially for the large cameras now available, the compensation of off-axial aberrations is also an important task. A correction system to compensate the spherical aberration and the off-axial coma is under development. The next step to follow towards ultra-high resolution will be a correction system to compensate the chromatic aberration. With such a correction system, a new area will be opened for applications for which the chromatic aberration defines the achievable resolution, even if the spherical aberration is corrected. This is the case, for example, for low-voltage electron microscopy (EM) for the investigation of beam-sensitive materials, for dynamic EM or for in-situ EM.

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