BCIP (5-bromo-4-chloro-3-indoyl phosphate) is the AP (alkaline phosphatase)-substrate which after dephosphorylation reacts further to give a dark-blue indigo dye as an oxidation product. INT (iodonitrotetrazolium) is the oxidant producing a red dye. The reaction product has a reddish-brown color and is insoluble in water.
Application:
INT/BCIP Stock Solution is used for the sensitive detection of alkaline phosphatase (AP) in blotting protocols, that includes:
Southern blot
Western blot
immunohistochemistry and immunocytochemistry
It has been used for colorogenic in situ hybridization.