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

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.

osmium tetroxide


osmic acid

a substance used in the fixing of cytological preparations that is characterized by the small amount of distortion it causes.


a chemical element, atomic number 76, atomic weight 190.2, symbol Os. See Table 6.

osmium tetroxide
a pathology stain and fixative; called also osmic acid.
References in periodicals archive ?
Osmium tetroxide has a pungent smell and comes from the Greek word for 'stench'.
In the blends containing block copolymer, the location of the block cannot be distinguished from the PB homopolymer, because in both cases the PB was stained dark using osmium tetroxide.
Osmium tetroxide was excluded from the other embryo set, which was dehydrated in graded ethanol series and infiltrated with LR White resin.
1 M cacodylate, postfixed in 1% S-collidine-buffered osmium tetroxide (1 hr), and then dehydrated in graded ethanol washes.
Specimens for SEM were preserved for one hour in 1%-2% osmium tetroxide in filtered seawater, rinsed and stored in distilled water, transferred to alcohol, critical-point-dried, and sputter-coated with carbon or gold (or both); microscopy was conducted at the SEM Laboratory of the National Museum of Natural History, Washington, DC.
OSMIUM tetroxide also known as osmic acid is a catalyst used in labs around the world.
Osmium tetroxide (4 wt% solution in water) was obtained from Electron Microscopy Sciences Co.
Samples were washed in phosphatebuffered saline solution, and then a second fixative, thiocarbohydrazide and osmium tetroxide, was applied to preserve lipids and large molecules.
Electron microscopy was performed with fresh tissues fixed in glutaraldehyde and postfixed in osmium tetroxide.
1 M phosphate buffer, postfixed in 1% osmium tetroxide, and embedded in epoxy resin.
The animals were sacrificed with ethylic acid inhalation and, then, testis fragments were collected, fixed in Karnovsky and post-fixed in osmium tetroxide.
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.