Acridine orange staining of the mammalian fibroblast cell coat.

Acridine orange selectively binds to glycos- and galactosaminoglycan (GAG) compounds 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.