Iron pyronine and alcian blue for staining acid mucin in plastic-embedded sections.

Iron pyronine Y and Alcian blue demonstrated sulfated and nonsulfated acid mucin, respectively, in plastic-embedded sections. Safran used in combination with these two dyes stained collagen and some reticulum fibers. Sulfated acid mucin was red, while nonsulfated acid mucin stained blue; collagen appeared yellow to greenish yellow. The iron pyronine Y-Alcian blue-safran staining method, when used as in the present article, produces excellent cellular visualization of sulfated and nonsulfated acid mucin.