A substance that has the ability to bind to silver solution and reduce it to a metallic form is described as what?

• A. Argentaffin
• B. Silver-positive
• C. Reducer
• D. Nucleophilic

Answer: (A)

Argentaffin describes tissue components that can bind silver ions and reduce them to metallic silver without any external reducer. This self-reducing property means the tissue itself acts as the reducing agent, producing a visible metallic silver deposit where those substances are present. That direct ability to both bind silver and convert it to metallic form is exactly what argentaffin denotes, which is why this is the best description.

The other terms don’t fit as well. A reducer would imply an external chemical reducing agent, not the tissue’s own capability. Silver-positive isn’t a standard histology descriptor for this phenomenon, and nucleophilic is a general chemical property, not a histological staining term.