The typical mucin special stains contain cationic (positively charged) dye molecules in solution at a specific pH. This is true in the case of mucicarmine, Alcian blue as well as the older metachromatic techniques that utilized such dyes as azure A or toluidine blue.

Mucicarmine is a special stain test (using a colouring stain) performed by pathologists to look for a type of protein called mucin. Mucin is made by specialized epithelial cells and it helps protect cells from damage.

3) Mucicarmine – A very specific stain for mucin of epithelial origin Long before immunohistochemical procedures were available, the Mucicarmine stain was used to verify the presence of signet-ring carcinoma, a rare form of highly malignant adenocarcinoma that produces mucin.

The mucin stain with the most specificity is mucicarmine, but it is very insensitive, so it is not really very useful. The stain that is the most sensitive is PAS, but you must learn how to interpret it in order to gain specificity. Colloidal iron stains are unpredictable. Alcian blue stains are simple, but have a lot of background staining.

Mucicarmine Stain: Mucicarmine stain is intended for the staining of mucin. Mucin is a secretion produced by a variety of epithelial cells and connective tissue cells. In certain intestinal inflammations or carcinomas, an excess of mucin is secreted by the epithelial cells.