title: A direct-colouring, metal precipitation method for the demonstration of arylsulphatases A and B.
abstract: A new, direct-colouring, metal precipitation method for the light microscopical demonstration of arylsulphatases A and B is described. It is based on the reducing capacity of nitrocatechol liberated by arylsulphatases from p-nitrocatechol sulphate. The reaction is carried out in Karnovsky-Roots' copper ferricyanide incubation mixture at pH 5.0 or 5.5; the nitrocatechol liberated reduces ferricyanide to ferrocyanide, which in turn forms a brown precipitate with copper that indicates enzyme activity. Enzyme activity was localized in cytoplasmic particles compatible with a lysosomal localization of the enzyme. The histochemical reaction was inhibited by phosphate, which has been shown to inhibit arylsulphatases A and B in biochemical determinations. The method described is technically simple, and sections can be mounted in synthetic resin after dehydration.
mesh_terms: D000311:Adrenal Glands / Q000201:enzymology*; D000328:Adult; D000818:Animals; D002396:Catechols; D002553:Cerebroside-Sulfatase / Q000032:analysis*; D002803:Chondro-4-Sulfatase / Q000032:analysis*; D005260:Female; D005292:Ferricyanides; D005295:Ferrocyanides; D006651:Histocytochemistry; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D008297:Male; D008722:Methods; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains; D013429:Sulfatases / Q000032:analysis*
chemical_list: D002396:Catechols; D005292:Ferricyanides; D005295:Ferrocyanides; D013429:Sulfatases; D002553:Cerebroside-Sulfatase; D002803:Chondro-4-Sulfatase; C021228:4-nitrocatechol sulfate