formazan
Pronunciation: fōr′mă-zan
Definition: A water-insoluble colored compound of the general structure, RNH—N=CR′—N=NR″, formed by reduction of a tetrazolium salt in the histochemical demonstration of oxidative enzymes; the R's are usually phenyl groups; examples include neotetrazolium, blue tetrazolium, and nitro blue tetrazolium.
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Examples: glitazone, GI cocktail, etc.

