A simple and highly reproducible staining method for fungi and other polysaccharide-rich microorganisms in animal tissues

A newly devised, simple and highly reproducible method for fungal staining is reported. Grocott's method, in which methenamine-silver nitrate solution is employed, has been widely used for the staining of fungi in tissue sections, but it frequently produces heavy background staining because of sudden and progressive reaction in the methenamine-silver nitrate solution. We therefore replace the latter solution with an ammoniacal silver nitrate solution. This new method yields more consistent results in fungal staining without background staining, since the reaction time in the ammoniacal silver nitrate solution is prolonged. The present method is considered superior to Grocott's method with regard to its simplicity and reproducibility.