3,3'-Diaminobenzidine tetrahydrochloride hydrate is a water-soluble preparation of 3,3'-Diaminobenzidine, a tetraamine biphenyl compound used as a histological stain for peroxidase activity. Reaction between 3,3'-Diaminobenzidine and peroxidase forms a visible insoluble product. This approach has been used to assay activity of glutamate decarboxylase in rat cerebellar sections and to detect horseradish peroxidase presence on cultured cell surfaces.
D 1357 (OTTO) 3,3'-Diaminobenzidine tetrahydrochloride, 98%+ Cas 868272-85-9 - used chromogenic peroxidase substrate for staining.