<prompt> Which of the following is a special stain used to diagnose fungal hyphae in tissues-Masson trichomeSilver methenamineCongo RedAlizarin Red  <response>: Ans. is b i.e., Silver methenamineo Gomori methamine silver stain GMS and periodic acid Schiff PAS are the two most common stains used to look for fungi in tissues and cytology specimens. 