Experiments on Fixation for Electron Microscopy 2. Alkalized Osmium Tetroxide

1962 ◽  
Vol s3-103 (63) ◽  
pp. 287-296
Author(s):  
S. K. MALHOTRA
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Potassium Acetate ◽  
Exocrine Cells ◽  
Osmium Tetroxide Solution ◽  
Convoluted Tubules ◽  
Test Objects ◽  
Proximal Convoluted Tubules

The effect of fixation with osmium tetroxide solution, made alkaline by the addition of potassium acetate, was studied by electron microscopy. Exocrine cells of the pancreas and the cells of the first (‘proximal’) convoluted tubules of the kidney of the mouse were used as test-objects. Partially prepolymerized methacrylate was used for embedding. The preservation of the various cell inclusions was similar to what is generally produced after fixation with Palade's buffered osmium tetroxide.

Experiments on Fixation for Electron Microscopy

1962 ◽  
Vol s3-103 (61) ◽  
pp. 5-15
Author(s):  
S. K. MALHOTRA
Keyword(s):  
Electron Microscopy ◽  
Proximal Tubule ◽  
Electron Micrographs ◽  
Osmium Tetroxide ◽  
Simple Solution ◽  
Distilled Water ◽  
Exocrine Cells ◽  
Osmium Tetroxide Solution ◽  
Test Objects

The effect of fixation with a simple solution of osmium tetroxide in distilled water was studied by electron microscopy. Exocrine cells of the pancreas and cells of the proximal tubule of the kidney of the mouse were used as test-objects. Partially prepolymerized methacrylate was used for embedding. There did not appear to be any marked disorganization of the cell inclusions. The appearance of the inclusions in the electron micrographs was similar to what is generally seen after fixation with the buffered osmium tetroxide solution of Palade.

scholarly journals STUDIES ON THE GOLGI APPARATUS BY ELECTRON MICROSCOPY WITH PARTICULAR REFERENCE TO AOYAMA'S TECHNIQUE

1956 ◽  
Vol 2 (4) ◽  
pp. 395-402 ◽  
Author(s):  
Dennis Lacy ◽  
Cyril E. Challice
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Osmium Tetroxide ◽  
Silver Impregnation ◽  
Impregnation Method ◽  
Exocrine Cells ◽  
Golgi Membranes ◽  
Osmium Tetroxide Solution

1. Aoyama's silver impregnation method for the Golgi apparatus has been used on exocrine cells of the pancreas of the mouse and studied by electron microscopy in order to determine as precisely as possible where the silver is deposited. Similar cells have also been fixed in buffered osmium tetroxide solution and compared with cells treated by the silver technique. 2. Examination of the Aoyama preparations usually revealed a light deposition of silver in the cytoplasm (hyaloplasm or matrix) and a heavy deposition of silver around a series of closely apposed vacuoles. The heavy deposition of silver was regarded as revealing the chromophilic region of the Golgi apparatus while the vacuoles were identified as the chromophobic component. 3. Comparison of the silver preparations with those fixed in buffered osmium tetroxide solution showed that the silver was primarily deposited in the region of the Golgi membranes.

Field Emission Scanning Electron Microscopy Of Mouse Cerebellar Synaptic Contacts

2000 ◽  
Vol 6 (S2) ◽  
pp. 844-845
Author(s):  
O.J. Castejón ◽  
R. P. Apkarian ◽  
H. V. Castejón
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Cerebellar Cortex ◽  
Osmium Tetroxide ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Solution Ph ◽  
Osmium Tetroxide Solution ◽  
Scanning Electron

Samples of albino mice cerebellar cortex were processed by the cryofracture method for scanning electron microscopy and examined with the field emission scanning electron microscope (FESEM). Albino mouse cerebellar cortex was excised, cut into 1-2 mm slices and inmersed in 4% glutaraldehyde in O. l M phosphate buffer solution, pH 7.4, for 24h at 4°C; and postfixed for 1 h in a similarly buffered 1% osmium tetroxide solution. Specimens were dehydrated in a graded serie of ethanol (30, 50, 70, 80, 90 2x100%) prior to wrapping individual tissue pieces in preformed absolute ethanol filled parafilm cryofracture packets. Rapid freezing of packets was performed by plunging into LN2. First, the packet was transferred from the LN2 storage vessel with LNT chilled forceps in order to avoid themial damage. Secondly, the cooled fracture blade was removed from the LN2, the packet was orientated under the blade, and immediately struck with a heavy tool.

scholarly journals ELECTRON PROBE ANALYSIS OF CATIONIC SPECIES IN PYROANTIMONATE PRECIPITATES IN EPON-EMBEDDED TISSUE

1969 ◽  
Vol 17 (2) ◽  
pp. 102-106 ◽  
Author(s):  
BERNARD P. LANE ◽  
EUGENE MARTIN
Keyword(s):  
Electron Microscopy ◽  
Electron Probe ◽  
Osmium Tetroxide ◽  
Vas Deferens ◽  
Apical Plasma Membrane ◽  
Mouse Vas Deferens ◽  
Electron Probe Analysis ◽  
Osmium Tetroxide Solution ◽  
Potassium Pyroantimonate

Electron microscopy of Epon-embedded mouse vas deferens eipthelium treated with buffered potassium pyroantimonate-osmium tetroxide solution revealed precipitates in the lamina propria and along the apical plasma membrane. Electron microprobe elemental analysis of adjacent sections demonstrated that the deposits contained sodium and antimony. Other cations noted to precipitate pyroantimonate in vitro were not present in large amounts compared to controls, and were randomly distributed.

Experiments on Fixation for Electron Microscopy

1963 ◽  
Vol s3-104 (65) ◽  
pp. 123-127
Author(s):  
S. K. MALHOTRA
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Osmium Tetroxide ◽  
Proximal Convoluted Tubule ◽  
Mitochondrial Matrix ◽  
Zymogen Granules ◽  
Exocrine Cells ◽  
Acid Ph ◽  
Pancreatic Exocrine ◽  
Tubule Cells

The effect of fixation with acidified solutions of osmium tetroxide (pH 1.5 to 3.5 has been studied on the first (proximal) convoluted tubule cells of the kidney and the pancreatic exocrine cells of the mouse, by electron microscopy. Partially prepolymerized methacrylate was used for embedding. The various membranous structures and the ribosomes retain their individuality even after prolonged fixation in solutions containing 5% acetic acid (pH 1.5). However, the mitochondrial matrix and the ground cytoplasm are not preserved; the zymogen granules are also partially washed out.

scholarly journals Electron Microscopy of Hemosiderin: Presence of Ferritin and Occurrence of Crystalline Lattices in Hemosiderin Deposits

1958 ◽  
Vol 4 (1) ◽  
pp. 55-58 ◽  
Author(s):  
Goetz W. Richter
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Iron Hydroxide ◽  
Human Beings ◽  
Cytoplasmic Organelles ◽  
Convoluted Tubules ◽  
Hemosiderin Deposits ◽  
Proximal Convoluted Tubules

Injections of hemoglobin were given to rats in order to produce hemosiderosis, and selected hemosiderin granules in sectioned cells of proximal convoluted tubules were studied by means of electron microscopy. When examined at high resolution, many of the dense particles that were present in hemosiderin granules proved to have the structure that characterizes the iron hydroxide micelles of molecular ferritin. In some hemosiderin deposits the dense particles formed lattices similar to those present in sections of crystalline ferritin. Such ordered arrangement of dense particles was encountered inside as well as outside of the cytoplasmic organelles for which the name "siderosomes" has been proposed previously, and which may be derived from mitochondria. Study of hemosiderin granules in hepatic parenchymal and reticuloendothelial cells of human beings yielded similar results. The findings confirm the inference that ferritin is a component of hemosiderin, and they indicate that some of the so called hemosiderin granules are crystals of ferritin.

Experiments on Fixation for Electron Microscopy

1963 ◽  
Vol s3-104 (66) ◽  
pp. 155-167
Author(s):  
S. K. MALHOTRA
Keyword(s):  
Electron Microscopy ◽  
Sodium Acetate ◽  
Butyl Methacrylate ◽  
Distilled Water ◽  
Exocrine Cells ◽  
Alkaline Side ◽  
Veronal Buffer ◽  
Tubule Cells ◽  
Test Objects

Michaelis's sodium acetate / sodium veronal buffer is generally used for holding the pH of fixing solutions for electron microscopy at about pH 7.3 to 7.5. The acetate, however, has no buffering action on the alkaline side of neutrality. Experiments were therefore made to study the effect on preservation of cellular constituents when sodium acetate is omitted from Palade's (or its variants) and Luft's fluids. Exocrine cells of the pancreas, convoluted tubule cells of the kidney, and the testes of the mouse were used as test-objects, n-butyl methacrylate (generally partially prepolymerized) and epikote 812 were used for embedding. The preservation visualized in the micrographs did not seem to suggest any marked differences in the quality of fixation from that produced by fixation in Palade's and Luft's fluids. However, there is some evidence that comparable micrographs could be produced by fixation in simple solutions of OsO4 in distilled water and subsequent embedding in suitable media.

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

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