Transmission Electron Microscope Studies of Polymers Stained with Ruthenium and Osmium Tetroxide

Author(s):  
J. S. Trent ◽  
P. R. Couchman ◽  
J. I. Scheinbeim
Author(s):  
R. C. Caughey ◽  
U. P. Kalyan-Raman

In a period of two years we have analyzed 50 muscle biopsies using the transmission electron microscope. Six nonspecific structures consisting of filamentous bodies, tubular aggregates, paracrystalline mitochondrial inclusions, honeycomb arrays, concentric laminated bodies, and finger print profiles were observed in 47 of 50 cases. In order to know the significance of these structures in muscle biopsies, we correlated their occurrence with their clinical history, histological findings, and histochemistry.The biopsies were initially fixed in 2.5% glutaraldehyde (pH. 7.5, 500 mOsm), then randomly minced and post fixed in 1% osmium tetroxide. All biopsies were processed with and without uranyl acetate en bloc staining in Walpole's buffer before ethanol dehydration. They were embedded in Epon 812 epoxy resin, sectioned, and stained with uranyl acetate and lead citrate before evaluation with a JEOL, JEM 100 C Transmission Electron Microscope. All grid squares of six different blocks were scanned to evaluate the ultra-structural pathology.


Author(s):  
R. D. Specian ◽  
V. F. Allison ◽  
J. E. Ubelaker

Although the scolex is the major area of contact between a cestode and its host, most fine structural studies have concentrated on the rest of the body. Davey and Breckenridge postulated, from histochemical data, that neurosecretory cells were present in the scolex of Hymenolepis diminuta. Such cells have been suggested to function in affecting growth and maturation of the strobila. Since a previous study by Rothman failed to determine such cells, the present study was undertaken.Specimens were collected from previously infected laboratory rats, fixed in paraformaldehyde, post-fixed in osmium tetroxide and embedded in Maraglas. Sections were examined on the Hitachi HU11B-2 transmission electron microscope.


Author(s):  
L. Faso ◽  
E. Rappa ◽  
G. Vernon ◽  
R. Witkus

Although hemocyanin, an oxygen binding protein, is found freely dissolved in the hemolymph of isopods its site of synthesis is still unknown.Circulating blood cel Is such as granular hemocytes have been implicated in hemocyanin synthesis in a number of arthropods including Astacus astacus and Homarus vulgaris. Circulating blood cells of Armadillidium vulgare were examined using a transmission electron microscope (TEM) for evidence of hemocyanin synthesis.For each experiment hemolymph was collected from twenty adult A. vulgare and fixed for 1 hour in 200 uL of 3.5% glutaraldehyde in 0.1M sodium cacodylate buffer pH 7.4 with 0.05% calcium chloride added. Hemolymph was then centrifuged at 3000 rpm in an IEC-DPR-6000 centrifuge for 15 minutes at 15 degrees centigrade. The supernatant was removed, and the resulting pellet was washed with three changes of sodium cacodylate buffer. Postfixation of the pellet was done in 1% osmium tetroxide for 1 hour.


2002 ◽  
Vol 10 (5) ◽  
pp. 20-23
Author(s):  
Paul Beauregard

Recently, there was a suggestion on the MSA listserver about the use of osmium tetroxide (OsO4 and how to handle it. One suggestion was that ampoules be scored, placed in a glass jar, and the ampoule smashed to release the contents. This seemed like a very unsafe way to use osmium tetroxide or ruthenium tetroxide. The purpose of this article is to suggest a way to generate smaller amounts of these compounds in a safer manner than smashing ampoules and wondering about what to do with the unused portion after staining or storing. Another purpose is to discuss a new reaction indicator for mainly osmium tetroxide. The use of a reaction specific indicator was mandatory for judging the level or degree to which staining had proceeded in thin sections for the transmission electron microscope (TEM).


Author(s):  
R. A. Waugh ◽  
J. R. Sommer

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.


Author(s):  
Sanford H. Vernick ◽  
Anastasios Tousimis ◽  
Victor Sprague

Recent electron microscope studies have greatly expanded our knowledge of the structure of the Microsporida, particularly of the developing and mature spore. Since these studies involved mainly sectioned material, they have revealed much internal detail of the spores but relatively little surface detail. This report concerns observations on the spore surface by means of the transmission electron microscope.


Author(s):  
H. Tochigi ◽  
H. Uchida ◽  
S. Shirai ◽  
K. Akashi ◽  
D. J. Evins ◽  
...  

A New High Excitation Objective Lens (Second-Zone Objective Lens) was discussed at Twenty-Sixth Annual EMSA Meeting. A new commercially available Transmission Electron Microscope incorporating this new lens has been completed.Major advantages of the new instrument allow an extremely small beam to be produced on the specimen plane which minimizes specimen beam damages, reduces contamination and drift.


Author(s):  
G. Cliff ◽  
M.J. Nasir ◽  
G.W. Lorimer ◽  
N. Ridley

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.


Author(s):  
R. Sinclair ◽  
B.E. Jacobson

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).


Author(s):  
J.N. Chapman ◽  
P.E. Batson ◽  
E.M. Waddell ◽  
R.P. Ferrier

By far the most commonly used mode of Lorentz microscopy in the examination of ferromagnetic thin films is the Fresnel or defocus mode. Use of this mode in the conventional transmission electron microscope (CTEM) is straightforward and immediately reveals the existence of all domain walls present. However, if such quantitative information as the domain wall profile is required, the technique suffers from several disadvantages. These include the inability to directly observe fine image detail on the viewing screen because of the stringent illumination coherence requirements, the difficulty of accurately translating part of a photographic plate into quantitative electron intensity data, and, perhaps most severe, the difficulty of interpreting this data. One solution to the first-named problem is to use a CTEM equipped with a field emission gun (FEG) (Inoue, Harada and Yamamoto 1977) whilst a second is to use the equivalent mode of image formation in a scanning transmission electron microscope (STEM) (Chapman, Batson, Waddell, Ferrier and Craven 1977), a technique which largely overcomes the second-named problem as well.


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