Some Morphologic Features of Axial Fibers and Body Fibrils of Treponemata

1970 ◽  
Vol 28 ◽  
pp. 110-111
Author(s):  
Ronald H. Jones ◽  
Zensaku Yoshii ◽  
Oscar J. Carver
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Phosphotungstic Acid ◽  
Defined Medium ◽  
Ammonium Molybdate ◽  
Negative Staining ◽  
Rabbit Serum ◽  
Cell Pole ◽  
Internal Cell ◽  
Cell Layers

Four strains (Reiter, Kazan 2,4,5) of treponemata were cultivated at 37° C for 3-7 days in standard media containing complement inactivated rabbit serum (Cannefax, Spirolate) and in a defined medium devised by Johnson and his associates (unpublished data). Electron microscope preparations included cells which were unwashed (harvested), washed up to seven times, autolysed, or ruptured by explosive decompression. Each preparation was fixed with gluteraldehyde or left unfixed. Negative staining was performed using phosphotungstic acid (PTA - pH 7.2) or ammonium molybdate (AM - pH 7.0-7.2). Electron microscopy was done with a JEM 6A model at 80kV using a magnification range of 10,000-50,000X.The autolytic and disruption techniques were most effective for visualizing the ultrastructure of the more internal cell layers or moieties. The number of axial fibers (AF) arising from each cell pole varied from 4-7, six being the most common.

Electron microscopy of interphase chromosomes in situ; binding of permanganate to chicken erythrocytes

1976 ◽  
Vol 20 (2) ◽  
pp. 289-307
Author(s):  
H.G. Davies
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Protein Interaction ◽  
Phosphotungstic Acid ◽  
Intact Cell ◽  
Anomalous Behaviour ◽  
Protein Protein Interaction ◽  
Chicken Erythrocytes

From quantitative electron-microscope observations on the binding of permanganate to regions of erythrocytes and reticulocytes of known chemical composition, it is concluded that KMnO4, like phosphotungstic acid (PTA), binds preferentially to sites on proteins. Compared with PTA, KMnO4 binding exhibits less anomalous behaviour. The data support the hypothesis previously put forward that the 2 regions, or phases, in condensed chromatin differ in both molecular composition and concentration. The increase in binding to protein which occurs during nuclear haemolysis is interpreted in terms of protein-protein interaction in the chromatin of the intact cell.

The negative staining of "difficult" bacteria like Arthrobacter globiformis for electron microscopy

1974 ◽  
Vol 20 (6) ◽  
pp. 901-903 ◽  
Author(s):  
E. C. S. Chan ◽  
M. Gomersall ◽  
J. Bernier
Keyword(s):  
Electron Microscopy ◽  
Cell Suspension ◽  
Phosphotungstic Acid ◽  
Negative Staining ◽  
Arthrobacter Globiformis ◽  
Glutaraldehyde Fixation ◽  
Plain Agar

A method is suggested for the negative staining of "difficult" bacteria like Arthrobacter globiformis for electron microscopy when the usual procedures do not give satisfactory results. It involves glutaraldehyde fixation, and thorough washing and drying of the cell suspension on a grid sitting on a bed of plain agar, followed by a rapid flushing with 2% phosphotungstic acid.

The Influence of Ammonium Molybdate, Silicotungstic Acid and Phosphotungstic Acid on Function and Structure of Mitochondria

1970 ◽  
Vol 28 ◽  
pp. 70-71
Author(s):  
W. J. Mergner ◽  
R. Pendergrass ◽  
B. F. Trump
Keyword(s):  
Electron Microscopy ◽  
Phosphotungstic Acid ◽  
Rat Kidney ◽  
Kinetic Studies ◽  
Ammonium Molybdate ◽  
Silicotungstic Acid ◽  
Ion Permeability ◽  
Freeze Fracturing ◽  
Kidney Mitochondria ◽  
Negative Stain

A negative stain should produce no structural change in the specimen. Our results indicate that this is not the case with at least two negative stains. There is a spectrum of changes which depends on the stain used. The negative stain also causes functional alterations which involve three basic functional characteristics of the mitochondria: 1) oxidative phosphorylation, 2) electron transport and 3) ion permeability. Rat kidney mitochondria were resuspended in the negative stain for 15 minutes (except for kinetic studies). For electron microscopy they were: 1) directly applied to grids; 2) fixed with glutaraldehyde and OSO4 and embedded in Epon; and 3) prepared by freeze fracturing. Mitochondria stained with ammonium molybdate (AM) revealed two types of profiles. They had either a dense inner compartment without penetration of negative stain displaying the commonly observed image (Fig. 3 and 4). With penetration the inner membrane was studded with spheres, but the spheres were not on discernible stalks (Fig. #5).

ELECTRON MICROSCOPY OF ISOLATED PLANT MITOCHONDRIA AND PLASTIDS USING BOTH THE THIN-SECTION AND NEGATIVE-STAINING TECHNIQUES

1965 ◽  
Vol 43 (6) ◽  
pp. 647-655 ◽  
Author(s):  
D. F. Parsons ◽  
W. D. Bonner Jr. ◽  
J. G. Verboon
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Thin Section ◽  
Insect Cell ◽  
Preliminary Report ◽  
Animal Cell ◽  
Plant Mitochondria ◽  
Negative Staining ◽  
Staining Techniques

Six types of plant mitochondria have been isolated by improved techniques and examined with the electron microscope by the thin-section and negative-staining techniques. In general, the mitochondria appeared well preserved. There was minimal contamination by endoplasmic reticulum but some plastids were present. The morphology of the plant mitochondria is compared with that of animal cell mitochondria. Negative staining showed that the inner membranes were covered with projecting knob-like subunits, as previously described for animal and insect cell mitochondria. The outer membrane showed a characteristic pitted appearance that was apparently due to 28 Å holes in the membrane. A preliminary report is also given of the appearance of negatively stained membranes of chloroplasts.

Immune electron microscopy of haemocyanins from two southern african whelks

1978 ◽  
Vol 36 (2) ◽  
pp. 158-159
Author(s):  
Linda M. Stannard ◽  
Margaret Lennon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Outer Ring ◽  
Immune Electron Microscopy ◽  
Intertidal Zones ◽  
Central Belt ◽  
Cape Peninsula ◽  
Circular Contour

Burnupena cincta and Fusus verruculatus are two whelks which inhabit the intertidal zones of the Cape Peninsula shore. Their respiratory pigments, or haemocyanins, are morphologically similar in structure (Figs. 1 and 2) and appear in the electron microscope as short cylindrical rods about 34 nm in diameter and 36 nm high. Viewed side-on the molecules show regular banding suggesting a structure composed of six equidistant rings of sub-units. Occasionally the particles have the appearance of possessing a central “belt” in the position of the 3rd and 4th rows of sub-units. End-on views of the haemocyanin molecules show a circular contour with a dense outer ring and a less dense inner ring in which 10 definite sub-units may frequently be distinguished. A number of molecules display an extra central inner component which appears either as a diffuse plug or as a discrete ring-shaped core ± 8 nm in diameter.

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Application of Scanning Electron Microscopy to Medical Research

1969 ◽  
Vol 27 ◽  
pp. 12-13
Author(s):  
J. D. Hutchison
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Medical Research ◽  
Prosthetic Heart Valve ◽  
School Of Medicine ◽  
Transmission Electron ◽  
Definition Of ◽  
Mechanism Of Failure ◽  
The Brain ◽  
Scanning Electron

When the transmission electron microscope was commercially introduced a few years ago, it was heralded as one of the most significant aids to medical research of the century. It continues to occupy that niche; however, the scanning electron microscope is gaining rapidly in relative importance as it fills the gap between conventional optical microscopy and transmission electron microscopy.IBM Boulder is conducting three major programs in cooperation with the Colorado School of Medicine. These are the study of the mechanism of failure of the prosthetic heart valve, the study of the ultrastructure of lung tissue, and the definition of the function of the cilia of the ventricular ependyma of the brain.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

Phenomena Associated with Oxygen in Titanium

1967 ◽  
Vol 25 ◽  
pp. 310-311
Author(s):  
E. U. Lee ◽  
P. A. Garner ◽  
J. S. Owens
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Microstructural Changes ◽  
Electrolytic Polishing ◽  
Interstitial Impurities ◽  
Thin Foils ◽  
Transmission Electron ◽  
Iodide Titanium ◽  
Alpha Titanium

Evidence for ordering (1-6) of interstitial impurities (O and C) has been obtained in b.c.c. metals, such as niobium and tantalum. In this paper we report the atomic and microstructural changes in an oxygenated c.p.h. metal (alpha titanium) as observed by transmission electron microscopy and diffraction.Oxygen was introduced into zone-refined iodide titanium sheets of 0.005 in. thickness in an atmosphere of oxygen and argon at 650°C, homogenized at 800°C and furnace-cooled in argon. Subsequently, thin foils were prepared by electrolytic polishing and examined in a JEM-7 electron microscope, operated at 100 KV.

Albumins as Embedding Media for Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 422-423 ◽  
Author(s):  
J. L. Farrant ◽  
J. D. McLean
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Temperature ◽  
Biological Material ◽  
Globular Proteins ◽  
The Past ◽  
Antibody Staining ◽  
Thin Sectioning ◽  
Embedding Medium

For electron microscope techniques such as ferritin-labeled antibody staining it would be advantageous to have available a simple means of thin sectioning biological material without subjecting it to lipid solvents, impregnation with plastic monomers and their subsequent polymerization. With this aim in view we have re-examined the use of protein as an embedding medium. Gelatin which has been used in the past is not very satisfactory both because of its fibrous nature and the high temperature necessary to keep its solutions fluid. We have found that globular proteins such as the serum and egg albumins can be cross-linked so as to yield blocks which are suitable for ultrathin sectioning.

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