Which technique could be used as an alternative to demonstrate the same tissue component that is stained rose in the described context?

• A. Methenamine silver
• B. PAS
• C. Alcian blue pH 2.5
• D. Crystal violet

Answer: (A)

Highlighting basement membranes can be done with more than one staining approach because their carbohydrate-rich components react with different chemical methods. If a tissue component appears rose with aPeriodic acid–Schiff (PAS)–type stain, that color comes from the staining of polysaccharides and glycoproteins in the basement membrane. An alternative technique to demonstrate the same structure is methenamine silver staining (Gomori methenamine silver). This method deposits silver onto the basement membranes (and reticular fibers) through a reaction involving aldehyde groups created by oxidation, producing a strong dark/black outline that clearly delineates the membrane. In practical terms, it provides similar visual confirmation of the basement membrane’s presence, just using a different chemical basis than PAS. The other options either target different tissue components or produce colors not associated with highlighting basement membranes, so they don’t serve as suitable alternatives for this specific structure.