Osmium tetroxide
SIGMA/O5500 - Sealed ampule.
Synonym: Osmium(VIII)-oxide; ‘Osmic acid’
CAS Number: 20816-12-0
Empirical Formula (Hill Notation): O4Os
Molecular Weight: 254.23
EC Number: 244-058-7
MDL Number: MFCD00011150
Linear Formula: OsO4
Product Type: Chemical
| bp | 130 °C (lit.) |
| form | powder |
| InChI | 1S/4O.Os |
| InChI key | VUVGYHUDAICLFK-UHFFFAOYSA |
| mp | 39.5-41 °C (lit.) |
| Quality Level | 200  |
| reaction suitability | reagent type: oxidant |
| SMILES string | O=[Os](=O)(=O)=O |
| vapor density | 8.8 (vs air) |
| vapor pressure | 7 mmHg ( 20 °C) |
| 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. |
| 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. |
| Other Notes: | Due to the hazardous nature of osmium tetroxide, it is recommended to use an ampule opener when using this chemical. |
| Packaging: | 1 g in ampule |
| Packaging: | 250 mg in ampule |
| Symbol |   GHS05,GHS06 |
| Signal word | Danger |
| Hazard statements | H300 + H310 + H330 - H314 |
| Precautionary statements | P260 - P270 - P280 - P303 + P361 + P353 - P304 + P340 + P310 - P305 + P351 + P338 |
| Hazard Codes | T+ |
| Risk Statements | 26/27/28-34 |
| Safety Statements | 7/9-26-45 |
| RIDADR | UN 2471 6.1 / PGI |
| WGK Germany | WGK 1 |
| bp | 130 °C (lit.) |
| mp | 39.5-41 °C (lit.) |
| UNSPSC | 12171500 |