Acridine orange staining of the mammalian fibroblast cell coat

Summary Acridine orange selectively binds to glycos- and galactosaminoglycan (GAG) compunds in the presence of Na⁺ in low concentrations. We have worked out a cytochemical method, which is suitable for the specific demonstration of surface GAG components. The method consists of a glutaraldehyde prefixation, an acridine orange block-staining for 48 h and an OsO₄ postfixation for some hours. The specificity of the staining was verified with the help of fluorimetric-in vitro-measurements and enzymatic digestions, respectively.