Tetrazolium salts are reduced by various substances. On fresh, non- frozen sections it is possible to put in evidence the endogenous reduction. On sections obtained by congelation or frigodessication, this reductasis is destroyed. The addition of a substrate, such as succinic acid, brings into evidence the succinohydrogenasis. Other substrates may be used, such as substances with sulfhydrile functions then sulfhydrases occur. On fixed sections, included or not with paraffin, at pH 10, one detects, in principle, the sulfhydrile functions. With pH 12.8 reducing glucides are essentially characterized. Those are endogenous substrates. Other substances may also be present and they are considered in their relations with the lipids. Finally, tetrazolium salts may serve as life colorants.
Trans. of Annales d'Histochimie (France) v1 p199-212 1956.