Combined Aldehyde-Fuchsin and Periodic Acid-Schiff Staining of the Pituitary

Aldehyde-fuchsin and the periodic acid-Schiff procedure can be applied in sequence to the same tissue section and combined with a stain for acidophils, such as orange G, for routine analysis of the pituitary. This is made possible by fixation in a mixture containing 5% chrome-alum, 5% HgCl₂ and 5% formalin; control of the pH and the activity of the aldehyde-fuchsin; and increased sensitivity of the Schiff reagent, effected by reducing its SO₂ content. Although designed especially for the pituitary, the procedure is also applicable to other histological problems.