Which of the following stain is used for visualising degenerated fungi in tissue?
**Core Concept**
The question is testing the ability to identify a specific histological stain used for detecting degenerated fungi in tissue samples. Histopathological staining techniques are crucial in diagnosing various fungal infections, and recognizing the appropriate stain for visualizing fungi is essential.
**Why the Correct Answer is Right**
The correct answer is Gomori's Methenamine Silver (GMS) stain. This stain is specifically designed to highlight the fungal elements, especially the hyphae and spores, in tissue sections. GMS stain works by reacting with the silver ions, which are then deposited onto the fungal cell walls, making them visible under a microscope. This staining technique is commonly used in the diagnosis of fungal infections, particularly in cases where the fungi have degenerated or are present in small numbers.
**Why Each Wrong Option is Incorrect**
**Option A:** H&E stain is a general-purpose stain used for histopathological examination, but it is not specific for visualizing fungi. It stains the cellular and tissue architecture but does not highlight fungal elements.
**Option B:** PAS stain (Periodic Acid-Schiff) is used to detect glycogen and other carbohydrates in tissues, but it is not specific for fungi. While it can stain some fungal elements, it is not as sensitive as GMS stain for detecting degenerated fungi.
**Option C:** Alcian Blue stain is used to detect mucopolysaccharides in tissues, but it is not relevant for visualizing fungi.
**Option D:** This option is missing, but it is not relevant for visualizing fungi.
**Clinical Pearl / High-Yield Fact**
Remember that GMS stain is a specific stain for visualizing fungi, and it is particularly useful in cases where the fungi have degenerated or are present in small numbers. This stain is a key diagnostic tool in the histopathological examination of tissue samples suspected of containing fungal infections.
**Correct Answer:** C. Gomori's Methenamine Silver (GMS) stain.