(n.) A rare metallic element of the platinum group, found native as an alloy in platinum ore, and in iridosmine. It is a hard, infusible, bluish or grayish white metal, and the heaviest substance known. Its tetroxide is used in histological experiments to stain tissues. Symbol Os. Atomic weight 191.1. Specific gravity 22.477.
Example Sentences:
(1) Effects of fixation with glutaraldehyde (GA), glutaraldehyde-osmium tetroxide (GA-OsO(4)), and osmium tetroxide (OsO(4)) on ion and ATP content, cell volume, vital dye staining, and stability to mechanical and thermal stress were studied in Ehrlich ascites tumor cells (EATC).
(2) The modified osmium-urea method gave better results and was easier to perform than the collagenase method.
(3) Additionally, by ultrasonic vibration of tissues that had been subjected to prolonged osmium fixation, the epithelium was removed and such microdissected membranes similarly were examined.
(4) The renal tissue was fixed with a mixture of buffered picric acid-paraformaldehyde-glutaraldehyde and immunostained with the peroxidase-antiperoxidase method for the electron microscope with the following steps: antikallikrein antiserum, anti-IgG serum, peroxidase-antiperoxidase complex, 3-3' diaminobenzidine-H2O2, and post-staining with osmium tetroxide.
(5) It was also found that tritium release also occurred, although to a lesser extent, when tissues were fixed in glutaraldehyde or osmium tetroxide using collidine as a buffer, and this release was not significant when collidine was applied to previously fixed tissues.
(6) In accordance with the physiological experiments, electronopaque pyroantimonate precipitate containing calcium was found in the lumina of caveolae, but not in any intracellular structures close to the plasma membrane, when the relaxed fibers were fixed in a 1% osmium tetroxide solution containing 2% potassium pyroantimonate.
(7) The addition of oxalate to a suspension of rabbit peritoneal neutrophils before fixation with glutaraldehyde and postfixation with osmium tetroxide-antimonate greatly enhanced the amount of calcium antimonate precipitate subsequently detectable with the electron microscope.
(8) Ultrastructurally, hemolytic concentrations of tributyltin can be visualized in the electron microscope by osmium staining during fixation as electron-dense spheres penetrating the lipid bilayer of the erythrocyte plasma membrane.
(9) Their visualisation appeared to be enhanced when ruthenium red was incorporated n the glutaraldehyde-osmium fixative but only when sections were stained with heavy metal salts, indicating that the fimbriae and capsule were not predominantly polysaccharide in nature.
(10) Intravascular fat in tissue postfixed in osmium tetroxide, embedded in epoxy or paraffin, and stained with toluidine blue, hematoxylin, or Oil Red O is more easily visualized than in frozen tissue that is stained with Oil Red O.
(11) Mitotic cells were selectively removed from the cultures with 0.2 per cent trypsin and fixed in either osmium tetroxide or glutaraldehyde followed by osmium tetroxide.
(12) Human cochleae were fixed in glutaraldehyde, without the use of osmium.
(13) No reaction was observed in general with osmium-amine, with the exception of a few cases.
(14) Glutaraldehyde-fixed testes were stained "en bloc" with the Ur-Pb-Cu technique of Thiéry and Rambourg ('76) or post-fixed and stained with the osmium tetroxide-potassium ferrocyanide method of Karnovsky ('71).
(15) Insertion of 28 alternating AT residues at the EcoRV site of pBR322 generates an site hypersensitive to osmium tetroxide modification, that does not serve as a transcription start site.
(16) The osmium tetroxide fixation technique was used for determination of cell size and number.
(17) It uses carbohydrazide as an osmium bridging agent and both osmium tetroxide and uranyl acetate as electron staining agents.
(18) Parallel microsamples were fixed with osmium tetroxide and with glutaraldehyde followed by osmium tetroxide as previously used in this laboratory for the preservation of energy-linked mitochondrial configurations.
(19) A combination of 2% osmium tetroxide-2% uranyl acetate or 2% gallic acid alone resulted in optimum fixation as ascertained by least extraction of radiolabels.
(20) In those instances, the osmium-amine reacted not only in the outer surface of the mesentery, but also penetrated with no visible reaction all the way to the connective tissue where it was detected in the elastic layer.