[Histonet] Modified GMS Protocols

[Bob Richmond]

If you choose another oxidizing agent than CrO3 (such as KMnO4, potassium
permanganate) it's up to you either to find literature to back you up, or
to do the stain with appropriate controls for the fungus you're looking for.

Freida Carson (citation below) found that periodic acid, commonly
substituted for chromic acid in the GMS stain, would stain Histoplasma
capsulatum only with the periodic acid at 60 degrees C for an hour.

In North America (and I note that Gudrun Lang is in Austria) staining of
old Histoplasma capsulatum is the definitive test of the efficacy of the
stain. Since this organism doesn't occur in Europe, I don't know know what
fungus is the most challenging there.

Inconsistent Detection of Histoplasma capsulatum with Periodic Acid
Oxidation in the Grocott Methenamine-Silver Nitrate (GMS) Fungus Stain

Freida L. Carson, Jerry Fredenburgh, and John E. Maxwell
1. Department of Pathology, Baylor University Medical Center
2. Richard-Allan Scientific Kalamazoo MI
3. Glenwood Regional Medical Center, West Monroe LA

J Histotechnol [June] 1999;22:119

Bob Richmond
Samurai Pathologist
Maryville TN