scholarly journals THE ULTRASTRUCTURE OF HUMAN THYROGLOBULIN

1968 ◽  
Vol 128 (5) ◽  
pp. 1129-1136 ◽  
Author(s):  
B. Bloth ◽  
R. Bergquist
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Carbon Film ◽  
Gel Filtration ◽  
Staining Technique ◽  
Single Step ◽  
Inhibiting Activity ◽  
Sedimentation Constant ◽  
Maximal Diameter ◽  
Step Procedure

Thyroglobulin molecules purified in a single step procedure by gel filtration were studied in the electron microscope using the negative staining technique. The molecule had the shape of a flexible helix with two turns. Its length was about 220 A and the maximal diameter of the coiled part of the molecule was estimated to be 110 A. The pitch varied between 40 and 50 A. Thyroglobulin molecules dried in sodium tungstosilicate on a carbon film as for electron microscopy retained their hemagglutination-inhibiting activity and 19S sedimentation constant when redissolved in physiological buffer.

scholarly journals THE ULTRASTRUCTURE OF NORMAL AND PATHOLOGICAL IGM IMMUNOGLOBULINS

1968 ◽  
Vol 127 (3) ◽  
pp. 399-410 ◽  
Author(s):  
B. Chesebro ◽  
B. Bloth ◽  
S-E. Svehag
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Carbon Film ◽  
Negative Contrast ◽  
Antibody Activity ◽  
Outer Diameter ◽  
Central Ring ◽  
Fine Fiber ◽  
Contrast Technique ◽  
Normal Human

Free IgM immunoglobulins were examined in the electron microscope using the negative contrast technique. Normal human and rabbit IgM and Waldenström macroglobulins were indistinguishable from one another and revealed flexible spider-like particles with five appendages joining a central ring. The average total span of the molecules was 300 A. The appendages were about 125 x 30 A; the central ring had an outer diameter of approximately 100 A and an inner diameter of 40 A. Some purified 19S IgM preparations tended to form massive aggregates (≥50S) which, when examined in the electron microscope, revealed enormous clumps of IgM molecules whose appendages were entangled with one another. Electron microscopy of reduced-alkylated IgM revealed total absence of intact spider-like molecules. The predominating structure observed was a round electron-dense knob about 50 A in diameter which in some cases had a fine fiber-like extension with approximate dimensions 100 x 15 A. Rabbit and human IgM molecules with antibody activity to poliovirus dried in sodium tungstosilicate on a carbon film as in preparation for electron microscopy were shown to retain nearly 100% of their poliovirus neutralizing activity after redissolving in a physiological buffer.

Transmission Electron Microscopy study of lead sulfide whiskers

1989 ◽  
Vol 47 ◽  
pp. 444-445
Author(s):  
S.A. Mansour ◽  
R. Scholz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Lead Sulfide ◽  
Carbon Film ◽  
Flame Temperature ◽  
High Resolution Electron Microscopy ◽  
Spiral Coil ◽  
Transmission Electron

This paper describes a transmission electron microscopy (TEM) study of the structure and growth mechanism of lead sulfide (PbS) whiskers. PbS whiskers were grown inside the stainless steel nozzle of a kerosene burner. The nozzle had a 0.5 mm aperture, and was fitted with an Al-spiral coil to filter kerosene impurities. The burner was operated continuously for four weeks at a kerosene pressure of 2-3 bars and a flame temperature of about 350°C before the nozzle clogged. A thick black deposit of fine PbS whiskers was found inside the nozzle.TEM specimens were prepared by ultrasonically suspending the fine black powder in alcohol. The suspended particles were deposited on a perforated carbon film supported on a copper grid, and examined with a JEM-1200EX transmission electron microscope operated at 120kV accelerating voltage. A JEM-4000EX transmission electron microscope was used for high resolution electron microscopy.Fig. 1. shows an EM micrograph of typical PbS whiskers. Each appears to have a high-contrast core encapsulated in a lower contrast shell. The electron diffraction pattern of a single whisker protruding over a hole in the carbon film is shown in Fig. 2.

A microdiffraction study of Os10C(Co)24-2 in the Scanning Transmission Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 696-697 ◽  
Author(s):  
M. E. Mochel ◽  
R. I. Masel ◽  
J. M. Mochel
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Structural Information ◽  
Carbon Film ◽  
Scanning Transmission Electron Microscope ◽  
Metal Particles ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Small Metal Particles

Recent papers have discussed some of the difficulties in determining the structure of very small (<10Å) metal particles using electron microscopy. One of the ideas in the literature is that electron diffraction could provide structural information even under conditions where imaging is difficult. The purpose of the work reported here is to demonstrate that one can use electron diffraction techniques to obtain structural information about small metal particles, in this case 5Å osmium particles on a carbon film.

scholarly journals High-Level Expression, Functional Reconstitution, and Quaternary Structure of a Prokaryotic Clc-Type Chloride Channel

1999 ◽  
Vol 114 (5) ◽  
pp. 713-722 ◽  
Author(s):  
Merritt Maduke ◽  
Deborah J. Pheasant ◽  
Christopher Miller
Keyword(s):  
Quaternary Structure ◽  
Gel Filtration ◽  
Single Step ◽  
High Level Expression ◽  
Microbial Genomes ◽  
E Coli ◽  
Step Procedure ◽  
High Level ◽  
Eukaryotic Organisms ◽  
Detergent Micelles

ClC-type anion-selective channels are widespread throughout eukaryotic organisms. BLAST homology searches reveal that many microbial genomes also contain members of the ClC family. An Escherichia coli–derived ClC Cl− channel homologue, “EriC,” the product of the yadQ gene, was overexpressed in E. coli and purified in milligram quantities in a single-step procedure. Reconstitution of purified EriC into liposomes confers on these membranes permeability to anions with selectivity similar to that observed electrophysiologically in mammalian ClC channels. Cross-linking studies argue that EriC is a homodimer in both detergent micelles and reconstituted liposomes, a conclusion corroborated by gel filtration and analytical sedimentation experiments.

Electron Microscopy of hydrothermally treated gamma-alumina

1990 ◽  
Vol 48 (4) ◽  
pp. 236-237
Author(s):  
S.A. Mansour ◽  
M. Halabl ◽  
R. Scholz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Treatment Process ◽  
Carbon Film ◽  
Alumina Powder ◽  
Gamma Alumina ◽  
Pore Characteristics ◽  
Transmission Electron ◽  
Level Information

Transmission electron microscopy (TEM) was utilized to study the microstructural changes that take place as a result of treating gamma-alumina extrudates at various temperatures for different treatment times. The value of the study comes from the numerous uses of gamma-alumina, the most important being as a support for catalysts, and from its ability to obtain valuable submicron-level information related to pore structure by TEM. The pore characteristics of the extrudates were controlled through controlling the treatment process. Extrudates were heated in an autoclave at temperatures of 150, 200 and 300°C for treatment times of 1,2,4 and 8h.A JEOL JEM-1200EX transmission electron microscope (TEM) operating at 120 kV was used. The TEM specimens were prepared by crushing the extrudates in a mortar and ultrasonically suspending the fine gamma-alumina powder in alcohol. The suspended particles were deposited on a perforated carbon film supported on a copper grid.

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.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

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%.

Sign in / Sign up

Export Citation Format

Share Document