title: Tetrazolium salts and formazans.
abstract: The history of the tetrazolium salts and formazans goes back 100 years, to when Friese (1875) reacted benzene diazonium nitrate with nitromethane, to produce a cherry-red "Neue Verbindung". This was the first formazan. 19 years later, Von Pechmann and Runge (1894) oxidised a formazan to produce the first tetrazolium salt. Many hundreds of tetrazolium salts and formazans were prepared in the following years, but only a handful have found applications in biological research. This article has attempted to describe the properties of these compounds, and to illustrate how the tetrazolium salt-formazan reaction has been exploited to serve an extremely wide variety of functions.
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000266:history; D002621:Chemistry; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004579:Electron Transport; D005260:Female; D005562:Formazans / Q000138:chemical synthesis / Q000266:history / Q000378:metabolism; D006651:Histocytochemistry; D006666:History of Medicine; D008928:Mitochondria / Q000201:enzymology; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D010101:Oxygen Consumption; D051381:Rats; D013385:Succinate Dehydrogenase / Q000378:metabolism; D009626:Terminology as Topic; D013778:Tetrazolium Salts / Q000138:chemical synthesis / Q000266:history / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D005562:Formazans; D013778:Tetrazolium Salts; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D013385:Succinate Dehydrogenase