Ventana Medical Systems, Inc. GMS II Staining Kit 860-028

GMS II Staining Kit selectively demonstrates polysaccharides in the cell walls of fungi and other opportunistic organisms, such as Pneumocystis carinii. GMS Staining Kit is a modification of Gomori's Methenamine Silver procedure. Tissue, fungal and microbial cell wall polysaccharides are oxidized to aldehyde groups by GMS Oxidizer. Chromic acid suppresses weaker background staining of collagen fibers and basement membranes. Neutralizer removes excess chromic acid. GMS Silver A, a silver nitrate reagent, provides the silver ions. GMS Silver B provides the alkaline conditions that reduce the silver ions to metallic silver. Toner reagent contains gold chloride to form a more stable gold complex and remove the yellow tones from the tissue. Fixer, with thiosulfate, stops the reaction and removes any unreduced silver from the section. The purpose of this stain is primarily to distinguish pathogenic fungi, such as Aspergillus and Blastomyces, and other opportunistic organisms, such as Pneumocystis carinii in tissue sections. Light Green Counterstain is applied to provide contrasting background. The GMS Staining Kit stains fungus black against a light green background. Aspergillus hyphae appear as black filaments. Pneumocystis carinii organisms appear as clusters of helmet-shaped black spots.