Bacterioneuston examined with critical point drying and transmission electron microscopy

1977 ◽  
Vol 4 (3) ◽  
pp. 267-277 ◽  
Author(s):  
L. Y. Young
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Critical Point ◽  
Transmission Electron ◽  
Critical Point Drying

Scanning and Transmission Electron Microscopy of Human Lung in a Patient with Sarcoid-like Reaction

1974 ◽  
Vol 32 ◽  
pp. 14-15
Author(s):  
John H. L. Watson ◽  
Jessica Goodwin ◽  
E. Osborne Coates
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hypersensitivity Reaction ◽  
Light Microscopy ◽  
Critical Point ◽  
Clinical Evidence ◽  
Human Lung ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Transmission Electron

Biopsies of lung were taken at operation from a patient with semi-acute diffuse pulmonary infiltrates for study by TEM and SEM. Tissue by light microscopy showed non-caseating granulomas consistent with sarcoidosis. Clinical evidence suggested a hypersensitivity reaction related to inhalation of substance of undetermined nature. Samples were fixed in glutaraldehyde, cacodylate-buffered. They were critical point dried and coated with Au-Pd for SEM, and were handled appropriately for TEM in Araldite. Sections were contrasted with uranyl acetate and lead citrate.

A Preliminary Study of Thin Bird Disease

1981 ◽  
Vol 39 ◽  
pp. 602-603
Author(s):  
Ronald W. Davis ◽  
Samual Kenzy ◽  
Erik H. Stauber
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Weight Loss ◽  
Light Microscopy ◽  
Critical Point ◽  
Post Mortem ◽  
Post Mortem Examination ◽  
Transmission Electron ◽  
Half Strength ◽  
Preliminary Study

We have initiated a study of a disease that is usually fatal to domestic parakeets and canaries. We have called this syndrome “thin bird disease” for lack of a better name.Clinically, the disease is diagnosed after observing a bird that is thin, exhibits severe weight loss, lethargy, and ruffled feathers. Fecal smears of affected birds contain many very large, single-celled, rod-shaped bacteria measuring up to 1μm x 90μm.Post mortem examination of birds exhibiting external symptoms of the disease reveals an enlarged ventriculus (gizzard) that contains unmacerated seeds. A jelly-like mass is found in the ventriculus and pro-ventriculus of affected birds. This material contains bacteria morphologically identical to those found in fecal smears (Figs. 3, 4).Samples of ventriculus and pro-ventriculus from birds clinically diagnosed as diseased and normal were collected and processed for light microscopy, scanning and transmission electron microscopy. The specimens were fixed in half strength Karnovsky's fixative, post fixed in OsO4, and either embedded in plastic or critical point dried.

Rapid Chemical Dehydration of Mammalian Tissues for Scanning Electron Microscopy using 2 ,2-Dimethoxypropane

1976 ◽  
Vol 34 ◽  
pp. 340-341
Author(s):  
Morton D Maser ◽  
John J. Trimble
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laboratory Mouse ◽  
Transmission Electron ◽  
Critical Point Drying ◽  
Mammalian Tissues ◽  
Cervical Dislocation ◽  
Structural Preservation ◽  
Scanning Electron

Muller and Jacks used 2,2-dimethoxypropane (DMP) as a dehydrating agent for biological specimens prior to embedment, ultrathin sectioning, and examination by transmission electron microscopy. Acidified DMP reacts endothermically with water to produce methanol and acetone. Muller and Jacks demonstrated excellent fine structural preservation in a variety of specimens dehydrated with DMP.We have used the same method, prior to critical point drying, to prepare specimens for scanning electron microscopy (SEM) . Portions of the trachea, small intestine, and kidney from a laboratory mouse killed by cervical dislocation were fixed for 16 hours in cold 3% glutaraldehyde in 0.1 M phosphate buffer, pH 7.2.

Correlative light, scanning and Transmission Electron Microscopy of polyethylene glycol (PEG) embedded and subsequently de-embedded tissues

1989 ◽  
Vol 47 ◽  
pp. 894-895
Author(s):  
Hisatake Kondo
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Critical Point ◽  
Glass Slides ◽  
Transmission Electron ◽  
Peg 4000 ◽  
Gentle Agitation ◽  
Reliable Procedure

Our understanding of the detailed morphology of bioloqical specimens often requires the correlation between images of the surface by scanning electron microscopy (SEM) and of the underlining interior structure by light microscopy (LM) or transmission electron microscopy (TEM). In order to accomplish the correlation with high quality, the polyethylene glycol (PEG) embedding and subsequent deembedding has been revealed to be a simple and quite reliable procedure.Tissue or cell samples are fixed and dehydrated in ethanol according to the conventional procedures. Vials containing the specimens in 100% ethanol are warmed in an oven at about 60°C and approximately equal amount of pure molten PEG-4000 is added in the vials. PEG is easily dissolved by gentle agitation. Thereafter the specimens are transferred to pure molten PEG contained in well-dried gelatin capsules. After the specimens have been sunk to the bottom of the capsule, each capsule is immersed in liquid nitrogen to solidify PEG. Portions of the solidified PEG including the specimens are cut out with a razer blade and mounted with dental wax on supporting stubs fitting the collet of the microtome. The specimen blocks are sectioned with a well-dried glass or diamond knife. Wrinkle-free sections, 200-300 nm thick, can be easily obtained with some practice unless the room atmosphere is humid. The sections are picked up with a platinum loop filled with 2.5 % sucrose and mounted on glass slides for LM or formvar-coated grids for TEM, both of which have previously been treated with 0.1 % poly-L-lysine. For LM sections may be processed for immunohistochemistry. For TEM, sections on grids are put into a submerged grid holder in 90 % ethanol. The holder is transferred to 100 % ethanol and subsequently to a critical point apparatus with carbon dioxide. For SEM, the specimen blocks with its mirror-smooth face, after taking sections, is removed from the stubs and immersed in warm water to get rid of PEG. The blocks are then dehydrated in ethanol and critical point dried with carbon dioxide.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

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