<prompt> Common stain for fungal hyphae:Methylene blueGomori Methanamine silverCongo redOil red 0  <response>: Ans is b i.e Gomori Methanamine silver Ref. Chakraboy 2e 617 Gomori Methenamine Silver GMS and Periodic acid-Schiff PAS are the two most common stains used to look for fungi in tissues and in cytology specimens. The GMS stain is more sensitive than the PAS stain as it stains both ble and non-ble fungal elements which are refractory to other stains but it stains inflammatory cells lysosomes and tissue reticulin too in addition to fungi. PAS staining has the slight advantage that the morphology of the tissue adjacent to the fungi can be better visualized, but this can be addressed using a GMS stain and H and E counterstain which stains only tissue. 