[The mechanism of the tetrazolium reduction and the effect of phenazinmethosulfate (author's transl)].

Modern results of the literature form the basis for the presentation of a scheme which shows the reduction of tetrazolium salts and the action of phenazine methosulfate under histochemical conditions. The reduction of tetrazolium salts passes the radical state and it hapens principally on the niveau of the flavin proteins and the ubiquinone. The importance of the superoxide radical for the reduction of tetrazolium salts under aerobic conditions is emphasized.