[Staining properties and applicability of spectrally pure thionine and its isomeres (author's transl)].

Paraffin-embedded human and animal tissues were stained with spectrally pure thionine, 1,3-diaminophenthiazoniumchlorate and 1,7-diaminophenthiazoniumperchlorate. They were examined by light microscopy to determine their applicability in histologic diagnosis. Furthermore the effect of salts and of the type of dye solvent on the staining properties of histological preparations was being investigated. Essentially the following results were obtained: 1. All 3 dyes can be applied rapidly and unproblematically on all types of tissues. Under standardized conditions, i.e. dye concentration, length of staining time and kind of staining procedure, the results are reproducable. 2. Thionine and its isomeres, being basic dyes, demonstrate a special affinity for nuclei, but also do stain cytoplasm sufficiently well to make counter-staining methods unnecessary. 3. Thionine -- in contrary to its isomeres -- reacts metachromatically with certain cellular structural elements, i.e. RNA, acid mucopolysaccharides, mucin. This property aids in morphological diagnosis and additionally enlightens certain activity states. 4. Addition of salts interferes with the staining procedure. 5. Water has special significance as solvent. Furthermore the appearance and function of metachromasia, the influence of ethanol on the metachromatic reaction, the mode of action of anorganic salts are being discussed as well as the reciprocal action of biologic substrates with the dyes having been incorporated by them.