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O5500

Sigma-Aldrich

Osmium tetroxide

Sealed ampule.

Synonym(s):

Osmium(VIII)-oxide, ‘Osmic acid’

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About This Item

Linear Formula:
OsO4
CAS Number:
Molecular Weight:
254.23
EC Number:
MDL number:
UNSPSC Code:
12171500
PubChem Substance ID:
NACRES:
NA.47

vapor density

8.8 (vs air)

vapor pressure

7 mmHg ( 20 °C)

form

powder

reaction suitability

reagent type: oxidant

bp

130 °C (lit.)

mp

39.5-41 °C (lit.)

SMILES string

O=[Os](=O)(=O)=O

InChI

1S/4O.Os

InChI key

VUVGYHUDAICLFK-UHFFFAOYSA-N

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General description

Osmium tetroxide (OsO4) is a heavy tetrahedral, symmetrical molecule composed of osmium, a third-row transition metal. Osmium tetroxide is both a dye, and a non-coagulant fixative agent in electron microscopy primarily used for the examination of biological tissue components in the histopathology laboratory. Specimens are postfixed with osmium testroxide to ensure preservation of the lipids.

Application

Osmium tetroxide has been used as a fixative reagent for Brevibacterium mcbrellneri, and curcumin treated human lung cancer cell lines′ observation with a scanning electron microscope. It is also suitable as a fixative for ultrastructural analysis of Toxoplasma gondii′s skeletal muscle cells.

Biochem/physiol Actions

Osmium tetroxide chemically combines with lipids making them insoluble; only 7% of the lipids can be extracted after the fixation. Therefore, the cell membranes comprising phospholipids become black and electron-dense after fixation in osmium tetroxide. It is also used to fix small amount of fat maintained in sections during paraffin processing.

Other Notes

Due to the hazardous nature of osmium tetroxide, it is recommended to use an ampule opener when using this chemical.

pictograms

Skull and crossbonesCorrosion

signalword

Danger

Hazard Classifications

Acute Tox. 1 Dermal - Acute Tox. 2 Inhalation - Acute Tox. 2 Oral - Eye Dam. 1 - Skin Corr. 1B

Storage Class

6.1A - Combustible acute toxic Cat. 1 and 2 / very toxic hazardous materials

wgk_germany

WGK 1

flash_point_f

Not applicable

flash_point_c

Not applicable

ppe

Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges


Certificates of Analysis (COA)

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