Ultrastructural characteristics of sporidia of Ustilago

1989 ◽  
Vol 47 ◽  
pp. 786-787
Author(s):  
Patricia N. Hackney
Keyword(s):  
Electron Microscope ◽  
Type System ◽  
Tube Formation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
Transmission Electron ◽  
Ustilago Hordei ◽  
Silene Alba ◽  
The University

Ustilago hordei and Ustilago violacea are yeast-like basidiomycete pathogens ofHordeum vulgare and Silene alba respectively. The mating type system in both species of Ustilago is bipolar, with alleles, A,a, (U.hordei) and a1, a2 (U.violacea) at a single locus. Haploid sporidia maintain the asexual phase by budding, while the sexual phase is initiated by conjugation tube formation between the mating types during budding and conjugation.For observation of budding, sporidia were prepared by culturing the four types on YEG (yeast extract glucose) broth for 24 hours. After centrifugation at 5000g cells were either left unmated or mated in a1/a2,A/a combinations. The sporidia were then mixed 1:1 with 4% agar and the resulting 1mm cubes fixed in 8% gluteraldehyde and post fixed in osmium tetroxide. After dehydration and embedding cubes were thin sectioned with a LKB ultratome and photographed in a Zeiss 9s transmission electron microscope or in an AE1 electron microscope of MK11 1MEV at the High Voltage Electron Microscopy Center of the University of Wisconsin-Madison.

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.

Some Biological Applications of High Voltage Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 298-299
Author(s):  
Hans Ris
Keyword(s):  
High Voltage ◽  
Chromosome Structure ◽  
Nerve Fibers ◽  
Good Resolution ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
High Voltage Electron ◽  
One Year ◽  
The University

The High Voltage Electron Microscope Laboratory at the University of Wisconsin has been in operation a little over one year. I would like to give a progress report about our experience with this new technique. The achievement of good resolution with thick specimens has been mainly exploited so far. A cold stage which will allow us to look at frozen specimens and a hydration stage are now being installed in our microscope. This will soon make it possible to study undehydrated specimens, a particularly exciting application of the high voltage microscope.Some of the problems studied at the Madison facility are: Structure of kinetoplast and flagella in trypanosomes (J. Paulin, U. of Georgia); growth cones of nerve fibers (R. Hannah, U. of Georgia Medical School); spiny dendrites in cerebellum of mouse (Scott and Guillery, Anatomy, U. of Wis.); spindle of baker's yeast (Joan Peterson, Madison) spindle of Haemanthus (A. Bajer, U. of Oregon, Eugene) chromosome structure (Hans Ris, U. of Wisconsin, Madison). Dr. Paulin and Dr. Hanna are reporting their work separately at this meeting and I shall therefore not discuss it here.

High-voltage electron microscopy of unsectioned human lung alveolar walls

1986 ◽  
Vol 44 ◽  
pp. 224-225
Author(s):  
Jacob Bastacky
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
Human Lung ◽  
Freeze Fracture ◽  
High Voltage Electron Microscopy ◽  
Composite Image ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Transmission Electron ◽  
Surface Image

The lung presents a very thin tissue barrier (0.2 μm) to gas exchange with alveolar walls on the order of 10 ym thick. We found the highly energetic (1.5 MeV) beam of the high voltage electron microscope (HVEM) able to penetrate whoiemount unsectioned alveolar walls. Thus, it is possible to simultaneously image the two surfaces of the wall and the internal contents of the wall. The result resembles a high-resolution scanning electron microscope (SEM) surface image with a superimposed transmission electron microscope (TEM) image of internal structure. The composite image resembles a freeze fracture image; however, this technique has the advantage that the specimen is still present.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

The 1-MeV Electron Microscope Installation at the University of Colorado

1973 ◽  
Vol 31 ◽  
pp. 8-9 ◽  
Author(s):  
Mircea Fotino
Keyword(s):  
Electron Microscopy ◽  
Developmental Biology ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
National Institutes Of Health ◽  
Experimental Program ◽  
University Of Colorado ◽  
Transmission Electron ◽  
The University ◽  
Research Resources

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.

Contrast and Resolution in Alfresco Microscopy and Thick Specimens

1972 ◽  
Vol 30 ◽  
pp. 570-571
Author(s):  
J. R. Sellar ◽  
J. M. Cowley
Keyword(s):  
Solid Material ◽  
Cell Design ◽  
Current Interest ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Environmental Cell ◽  
Scanning Transmission ◽  
Conventional Transmission Electron Microscope ◽  
Transmission Microscope

Current interest in high voltage electron microscopy, especially in the scanning mode, has prompted the development of a method for determining the contrast and resolution of images of specimens in controlled-atmosphere stages or open to the air, hydrated biological specimens being a good example. Such a method would be of use in the prediction of microscope performance and in the subsequent optimization of environmental cell design for given circumstances of accelerating voltage, cell gas pressure and constitution, and desired resolution.Fig. 1 depicts the alfresco cell of a focussed scanning transmission microscope with a layer of gas L (and possibly a thin window W) between the objective O and specimen T. Using the principle of reciprocity, it may be considered optically equivalent to a conventional transmission electron microscope, if the beams were reversed. The layer of gas or solid material after the specimen in the STEM or before the specimen in TEM has no great effect on resolution or contrast and so is ignored here.

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).

Analysis of photographic emulsions for High-Voltage Electron Microscopy

1993 ◽  
Vol 51 ◽  
pp. 452-453 ◽  
Author(s):  
James R. Kremer ◽  
Paul S. Furcinitti ◽  
Eileen O’Toole ◽  
J. Richard McIntosh
Keyword(s):  
Electron Microscope ◽  
Optical Density ◽  
High Voltage ◽  
Noise Power ◽  
Limited Information ◽  
Modulation Transfer ◽  
Transmission Microscopy ◽  
High Voltage Electron Microscopy ◽  
Voltage Range ◽  
Voltage Electron

Characteristics of electron microscope film emulsions, such as the speed, the modulation transfer function, and the exposure dependence of the noise power spectrum, have been studied for electron energies (80-100keV) used in conventional transmission microscopy. However, limited information is available for electron energies in the intermediate to high voltage range, 300-1000keV. Furthermore, emulsion characteristics, such as optical density versus exposure, for new or improved emulsions are usually only quoted by film manufacturers for 80keV electrons. The need for further film emulsion studies at higher voltages becomes apparent when searching for a film to record low dose images of radiation sensitive biological specimens in the frozen hydrated state. Here, we report the optical density, speed and relative resolution of a few of the more popular electron microscope films after exposure to 1MeV electrons.Three electron microscope films, Kodak S0-163, Kodak 4489, and Agfa Scientia 23D56 were tested with a JEOLJEM-1000 electron microscope operating at an accelerating voltage of 1000keV.

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.

scholarly journals Rotation and twist of the central-pair microtubules in the cilia of Paramecium.

1980 ◽  
Vol 87 (1) ◽  
pp. 33-46 ◽  
Author(s):  
C K Omoto ◽  
C Kung
Keyword(s):  
Thin Section ◽  
Three Dimensional ◽  
Ciliary Movement ◽  
High Voltage Electron Microscopy ◽  
Central Pair ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
Left Handed ◽  
Thin Section Analysis ◽  
Metachronal Waves

The orientation and configuration of the central-pair microtubules in cilia were studied by serial thin-section analysis of "instantaneously fixed" paramecia. Cilia were frozen in various positions in metachronal waves by such a fixation. The spatial sequence of these positions across the wave represents the temporal sequence of the positions during the active beat cycle of a cilium. Systematic shifts of central-pair orientation across the wave indicate that the central pair rotates 360 degrees counterclockwise (viewed from outside) with each ciliary beat cycle (C. K. Omoto, 1979, Thesis, University of Wisconsin, Madison; C. K. Omoto and C. Kung, 1979, Nature [Lond.] 279:532-534). This is true even for paramecia with different directions of effective stroke as in forward- or backward-swimming cells. The systematic shifts of central-pair orientation cannot be seen in Ni++-paralyzed cells or sluggish mutants which do not have metachronal waves. Both serial thin-section and thick-section high-voltage electron microscopy show that whenever a twist in the central pair is seen, it is always left-handed. This twist is consistent with the hypothesis that the central pair continuously rotates counterclockwise with the rotation originating at the base of the cilium. That the rotation of the central pair is most likely with respect to the peripheral tubules as well as the cell surface is discussed. These results are incorporated into a model in which the central-pair complex is a component in the regulation of the mechanism needed for three-dimensional ciliary movement.

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