Staining of Fungi in Plastic-Embedded Tissue

Tissues embedded in plastic are sometimes stained with a special stain for fungi. Sections of plastic-embedded tissue were stained using both the periodic acid-Schiff (PAS) reaction and Grocott’s methenamine silver (GMS) method. The periodic acid-Schiff reaction is a more rapid and less complicated stain, which stained evenly. Grocott’s methenamine silver method stained inconsistently, occasionally caused sections to detach from the slides, and is a longer and more complicated stain. Thus, the periodic acid-Schiff reaction is recommended for demonstrating fungi in plasticembedded tissue.