BCIP is a colorimetric substrate for alkaline phosphatase.1,2 Upon enzymatic cleavage by alkaline phosphatase, an indoxyl intermediate is released and subsequently oxidized to produce water-insoluble indigo. It can be used to detect alkaline phosphatase activity by immunohistochemistry (IHC) or Western blot (WB).
1.Epstein, E., Wolf, P.L., Horwitz, J.P., et al.An indigogenic reaction for alkaline phosphatase in disk electrophoresisAm. J. Clin. Pathol.48(5)530-534(1967) 2.Wolf, P.L., Horwitz, J.P., Vasquez, J., et al.The indigogenic reaction for histochemical demonstration of alkaline and acid phosphataseExperientia23(3)183-185(1967)