Alcian Blue with Hyaluronidase is used to differentiate which mucins?

• A. Differentiates epithelial and connective tissue mucins
• B. Stains amyloid
• C. Identifies collagen
• D. Stains nuclei

Answer: (A)

Alcian blue staining at pH 2.5 targets acidic mucins, which include sulfated and carboxylated mucins. When you pre-treat with hyaluronidase, you are digesting hyaluronic acid and related glycosaminoglycans that are especially abundant in connective tissue mucins. This digestion reduces staining of connective tissue mucins, so the mucin that remains stained after treatment is the epithelial-type mucin. In other words, Alcian blue with hyaluronidase helps distinguish epithelial mucins from connective tissue mucins by removing the connective tissue component and leaving the epithelial mucins visibly blue.