Histochemical Demonstration of Acid Phosphatases With Naphthol AS-Phosphates

Abstract

A simple, reliable, and convenient azo-dye method for the demonstration of acid phosphatase and phosphamidase in paraffin-embedded tissues is described. The best results are obtained with frozen-dried tissues. Phosphates of naphthols AS-BI, AS-BS, AS-LC, and AS-TR are useful substrates (text-fig. 1, II). The stability and potential high chromogenicity of these substrates suggest their use in quantitative determinations. The present study indicates that acid phosphatase is not as sensitive an enzyme as previously assumed, and that with reasonable care it can be preserved even in mounted sections over a long period.