ON THE HISTOCHEMISTRY OF AZO GROUP-FREE THIAZOLE DYES

Abstract

Analysis of primuline, thioflavine S and thioflavine T acid and basic azo group-free thiazole dyes showed that they were built up from a number of components which were characterized by physicochemical methods. It was found that the isolated components, as well as related substances of known chemical composition, have characteristic staining properties. Factors involved in the staining mechanism of the dyes and of components—dye concentration, pH, aggregation of the dye molecules—were investigated and their roles are discussed. Selectivity of these fluorescent staining methods was also studied.