The technique shown in the image requires the use of which reagent?

• A. Diamine silver
• B. Silver nitrate
• C. Gold chloride
• D. Ammoniacal copper

Answer: (A)

Diamine silver is used because many silver-staining methods rely on a diamine-silver complex that is readily reduced to metallic silver by the tissue. This developer step deposits silver specifically where the targeted structures are present, making them visible as dark deposits. The other reagents either simply provide silver ions without developing them in the same way (silver nitrate), or they introduce different metals or colors (gold chloride, ammoniacal copper), and thus would not produce the same stain pattern seen with this technique.