Both Gomori reticulin and PASM stains are based on carbohydrate demonstration.

• A. True
• B. False
• C. Not sure
• D. N/A

Answer: (A)

Carbohydrate-containing substances are detected by forming aldehyde groups that drive the staining reaction. Gomori reticulin relies on argentaffin/argyrophilic staining of reticular fibers, where oxidation (often with permanganate) converts carbohydrate-rich components of these fibers into aldehydes that readily reduce silver, making the reticular network appear dark against a lighter background. PASM uses periodic acid to oxidize carbohydrates to aldehydes, and the Schiff reagent then binds those aldehydes to yield a magenta color; the methenamine silver step in PASM further enhances visualization of basement membranes and fungi. Because both techniques depend on carbohydrates being oxidized to aldehydes that enable deposition or detection, they are both based on carbohydrate demonstration.