[Method of counterstaining preparations for immunofluorescent studies of the pituitary]

To elucidate nonfluorescent structural elements of the hypophyseal parenchyma for immunofluorescent investigations, properties of some dyes most commonly applied for hypophysis staining have been studied. Such dyes as paraldehide-fuchsin, light green, orange G, chromotrop 2R, hematoxylin, eosin, fuchsin, azocarmin possess their own intensive luminescence and block immunofluorescence completely. Some other dyes (trypan blue, bromthymol blue, aniline blue, malachite green, methyl green) though not blocking immunofluorescence, they do not reveal hypophyseal cellular elements distinctly enough. Good results have been obtained with 0.3% water solution of toluidine blue, 0.5% solution of methylene light blue, methylene blue, as well as with Gram--Weigert's staining and with gallocyanin after Einarson. For special staining of corticotropocytes, the authors recommend 0.1% solution of bromphenol blue in barate buffer, pH 8.2.