A differential staining method for adenohypophyseal cells.

A modification of azan staining (Heidenhain, 1915) for a better differential demonstration than previously of adenohypophyseal cells is reported. Human hypophyses were fixed in Bouin's solution, washed in 70% alcohol, dehydrated and then embedded in paraffin. Sections of about 5 microns thickness were cut and mounted on albumin-coated glass slides. These sections were gently oxidized with a mixture of potassium permanganate and sulphuric acid, and then stained according to the original azan technique; thereafter a procedure of staining with aniline blue was added. With this improvement, human adenohypophyseal cells were clearly classified into six groups on the basis of the color and intensity of staining of the cytoplasm. The alpha-acidophilic cells were stained clear red with azocarmine and the epsilon-acidophilic cells, orange-red with orange G, respectively. With aniline blue, beta-basophilic cells stained a deep blue, while delta-basophilic cells were more weakly stained. The gamma-chromophobic cells were faintly stained red, and the ACTH-cells very faintly blue. Collagenous fibers developed a blue color, while erythrocytes were orange-red to red. This modified method produces much better results in differential staining of the adenohypophyseal cells than either the original azan or Masson-Goldner staining methods.