Proteolytic enzyme digestion in IHC can improve penetration and restore epitopes; what is another effect?

• A. Improves penetration of reagents and unmasking epitopes
• B. Stains lipids
• C. Inhibits antibody binding
• D. Destroys tissue morphology

Answer: (A)

Proteolytic enzyme digestion helps by breaking down cross-linked proteins from fixation, increasing tissue porosity so antibodies and reagents can diffuse more deeply and by removing masking proteins to reveal epitopes—this is the same dual benefit described. The best choice captures this additional effect: it improves penetration of reagents and unmasking epitopes. It does not stain lipids, it doesn’t inherently inhibit antibody binding (properly optimized digestion enhances binding), and while overdigestion can compromise tissue morphology, the useful additional effect being highlighted is the enhanced penetration and epitope exposure.