If the staining protocol includes an oxidation step, which two stains are most likely involved?

• A. Gomori reticulin and PASM
• B. Verhoeff and Aldehyde fuchsin
• C. Aldehyde fuchsin and PASM
• D. Gomori reticulin and Verhoeff

Answer: (A)

Oxidation steps in staining are used to generate reactive groups that let certain stains bond to specific tissue components. Gomori reticulin relies on an oxidation step to prepare tissue so silver can selectively deposit on reticular (reticulin) fibers, giving them a distinct dark outline. Periodic acid–Schiff with methenamine silver (PASM) hinges on the periodic acid part to oxidize carbohydrates and create aldehyde groups for the Schiff reaction, while the methenamine silver portion further enhances contrast in particular structures. Because both stains commonly require an oxidation step as part of their standard protocols, they’re the pair most likely to be involved when an oxidation step is specified. The other options include stains where oxidation is not a defining part of their routine procedures, so they’re less consistent with the given requirement.