DAB (3,3'Diaminobenzidine) is the most commonly used chromogen for IHC staining. In the presence of peroxidase such as HRP, DAB produces a brown, alcohol-insoluble precipitate.

BCIP/NBT substrate detects alkaline phosphatase in blotting and slide applications. It deposits a permanent dark purple stain on membrane sites bearing phosphatase and with the combination of BCIP(5-bromo-4-chloro-3indolyl-phosphate and NBT(nitrobluetetrazoleum) produces much higher sensitivity than either reagent separately.