Which stain is used to demonstrate epithelial mucin in tissue sections?

• A. Mayer mucicarmine
• B. Alcian blue
• C. Hematoxylin & Eosin
• D. Gram stain

Answer: (A)

Demonstrating epithelial mucin relies on a stain that binds the mucin glycoproteins inside epithelial cells and goblet cells so they stand out clearly. Mayer mucicarmine does exactly that, coloring epithelial mucin a bright rose-red against the rest of the tissue. This strong, specific red color makes mucin-producing cells easy to identify, which is why it’s the preferred stain for epithelial mucin in tissue sections. Alcian blue can highlight acidic mucins by turning them blue, but it doesn’t provide the same definitive red demonstration of epithelial mucin as mucicarmine. Hematoxylin & Eosin mainly shows general structure, not mucin, and Gram stain targets bacteria.