Grocott's methenamine silver stain

A liver biopsy stained using the grocott's methenamine silver stain demonstrating histoplasma (black round balls) in a granuloma.

In pathology, the Grocott-Gomori's (or Gömöri) methenamine silver stain, abbreviated GMS, is a popular staining method in histology. The stain was originally named after György Gömöri, the Hungarian physician who developed the stain.

It is used widely as a screen for fungal organisms. Particularly useful in staining carbohydrates.

It can be used to identify the yeast-like fungus Pneumocystis jiroveci which causes a form of pneumonia called Pneumocystis pneumonia (PCP) or pneumocystosis.

The cell walls of these organisms are outlined by the brown to black stain.

See also

• Methenamine