osmium tetroxide

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os·mic ac·id

(oz'mik as'id),
OsO4; a volatile caustic and strong oxidizing agent; colorless crystals, poorly soluble in water, but soluble in organic solvents; the aqueous solution is a fat and myelin stain and a general fixative for electron microscopy.
Synonym(s): osmium tetroxide
Farlex Partner Medical Dictionary © Farlex 2012

osmium tetroxide

A volatile poisonous pale yellow solid, OsO4, with a pungent smell, used as an oxidizing agent and in solution to stain and fix biological material, especially lipids. Also called osmic acid.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

osmium tetroxide


osmic acid

a substance used in the fixing of cytological preparations that is characterized by the small amount of distortion it causes.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
Suspects' conversations were eavesdropped on at the GCHQ electronic listening centre and police moved to disrupt the plot at an early stage before any osmium tetroxide was obtained.
For light microscopy analysis, one testis was fixed in Bouin and the sections stained with hematoxylin and eosin, while the other was fixed in Karnovsky's for 4 hours, post-fixed in osmium tetroxide 1% and in phosphate buffer for 2 hours, for electron microscopy.
The coverslips were washed with phosphate-buffered saline before being postfixated in 1% osmium tetroxide for 1 h.
OSMIUM tetroxide also known as osmic acid is a catalyst used in labs around the world.
The cells were then post-fixed in 2% osmium tetroxide and processed for transmission electron microscopy.
Samples were washed in phosphatebuffered saline solution, and then a second fixative, thiocarbohydrazide and osmium tetroxide, was applied to preserve lipids and large molecules.
For electron microscopy, small pieces of tissue were fixed in 2.5% glutaraldehyde, postfixed in osmium tetroxide, dehydrated with alcohol, and embedded in epoxy resin.
The fragments were then washed three times with 0.1 M phosphate buffer, pH 7.3, and post-fixed in 1% osmium tetroxide in the same buffer for 2 h.
It is believed a group of fanatical British-based Muslims planned to pack a lethal mix of explosives and osmium tetroxide, whose fumes are invisible and odourless, in rucksacks.
Tissues were deparaffinized for 1 h in xylene warmed to 60[degrees]C, rehydrated through a graded series of alcohols, postfixed in phosphate-buffered 2.5% glutaraldehyde and 1% osmium tetroxide, stained with 4% uranyl acetate, dehydrated through a graded series of alcohols and propylene oxide, and embedded in a mixture of Epon-substitute and Araldite.
The samples were placed in 1% osmium tetroxide in ASW for I h on ice and then washed 3 times in ASW.
The samples were postfixed for 1 hr with 1% veronal acetate-buffered osmium tetroxide. Ultrathin sections were stained in ethanolic uranyl acetate and lead citrate and examined by electron microscopy (JEM-200 FX; JEOL, Tokyo Japan).