A good Grocott methenamine silver stain shows organisms with which features?

• A. Crisp black cell wall and visible internal structure
• B. Blue-stained cell walls
• C. Pink cytoplasm
• D. Clear cytoplasm

Answer: (A)

The Grocott methenamine silver stain is designed to highlight fungal elements by depositing silver on their cell walls, producing a strong, dark outline against a pale background. Because the fungal wall components bind the silver, the walls appear crisp and black, which makes the organisms stand out clearly. In many preparations you can also observe internal details, such as septa or budding forms, because the stain provides enough contrast to reveal some internal fungal structures. Colors like blue for cell walls, pink cytoplasm, or clear cytoplasm don’t reflect how fungi are visualized with this stain, so they wouldn’t be expected in a well-performed GMS stain.