[Model studies in the histochemical investigation of hydrolases using tetrazolium salts]

As a model alkaline phosphatase and non-specific esterase were investigated with indoxyl substrates and 11 tetrazolium salts of different reducible substances in livers and kidneys of rat. Besides their localizing qualities, the reducibility of the used tetrazolium salts is the most important parameter for their use in histochemistry of hydrolases. The composition of the reaction products depends on the reducibility of the indicator and the pH of the reaction. The of phenazine methosulphate improves the indoxyl-tetrazolium techniques above all in the neutral and acid range.