From Biology-Online Dictionary | Biology-Online Dictionary


(Science: chemical) a water-insoluble coloured azo compound of the general structure, RNH-N==CR'-N==NR', formed by reduction of a tetrazolium salt in the histochemical demonstration of oxidative enzymes

Employing this reaction, oxidoreductase activity can be determined quantitatively in tissue sections by allowing the enzymes to act on their specific substrates in the presence of tetrazolium salts.

The R's are usually phenyl groups; examples include neotetrazolium, blue tetrazolium, and nitro blue tetrazolium.

Pharmacological action: indicators and reagents.