Which staining control uses skin as the test tissue?

• A. Gomori Burtner
• B. Cresyl Echt Violet
• C. Congo Red
• D. Brown & Brenn Gram

Answer: (A)

The main idea here is using a tissue that naturally contains the target structure as a positive control to verify a staining method works as intended. For the Gomori Burtner stain, which is a silver-based fungal stain, skin tissue is a classic positive control because skin commonly harbors fungal elements (dermatophytes and other fungi). The Gomori methenamine silver approach stains fungal cell walls dark, making the organisms stand out clearly against the tissue background when present. Using skin as the test tissue ensures the stain reliably highlights organisms if they are there, validating the staining procedure.

The other stains serve different purposes: Cresyl Echt Violet targets neuronal Nissl substance, Congo Red highlights amyloid deposits, and Brown & Brenn Gram is a Gram stain for bacteria in tissues. None are typically used with skin as a standard positive control for demonstrating fungal elements, so they don’t fit this specific testing scenario.