In Mayer mucicarmine staining, what color does mucin typically appear?

• A. Deep rose to red
• B. Blue
• C. Black
• D. Yellow

Answer: (A)

Mayer mucicarmine staining is used to detect mucins, which are acidic mucopolysaccharides produced by goblet cells and mucin-producing tissues. The dye binds specifically to those mucins, giving them a distinct color that stands out against the rest of the tissue. In this stain, mucin appears deep rose to red, providing a strong contrast against the blue counterstain that colors nuclei and other tissue elements. This red coloration helps pathologists identify mucin-producing cells and tissues, which is especially useful in diagnosing mucinous tumors or mucin-secreting lesions. Hence, the color you see for mucin with Mayer mucicarmine is deep rose to red.