Alkaline phosphatase enzyme substrate

Alkaline phosphatase (AP) buffer

5-Bromo-4-chloro-3-indolyl phosphate (BCIP) (50 mg/mL)

Nitro blue tetrazolium (NBT) (50 mg/mL)

Add 33 μL of NBT to 5 mL of AP buffer and mix well. Add 16.5 μL of BCIP and mix well. Prepare this solution not more than 1 h before use, and keep it protected from light.