5-Bromo-4-chloro-3-indolyl phosphate

Chembox new
Name = BCIP
ImageFile = BCIP.svg
ImageName = 5-Bromo-4-chloro-3-indolyl phosphate
IUPACName = 5-Bromo-4-chloro-3-indolyl phosphate
OtherNames = BCIP
Section1 = Chembox Identifiers
SMILES =
CASNo =
RTECS =
Section2 = Chembox Properties
Formula = C₈H₆BrClNO₄P
MolarMass = 433.6 g/mol
Appearance = Colorless
Density =
Solubility = very low solubility in water or lipid
MeltingPt =

5-Bromo-4-chloro-3-indolyl phosphate (BCIP) is a chemical compound used in immunoblotting, in situ hybridization, and immunohistochemistry, with nitro blue tetrazolium chloride (NBT), for sensitive colorimetric detection of alkaline phosphatase. [http://www.sigmaaldrich.com/catalog/search/ProductDetail/SIGMA/B1026] NBT serves as the oxidant (and gives also dark blue dye) and BCIP is the alkaline phosphatase substrate. Alkaline phosphatase is commonly conjugated to secondary antibodies.

:BCIP (colorless)^oxidation→ blue precipitate.

BCIP-NBT naturally forms this bluish purple precipitate over time; however, alkaline phosphatase speeds up the process 1000 fold. BCIP binds very tightly in the alkaline phosphatase active site, but when NBT reacts with BCIP, it is released from the enzyme and the colored precipitate forms.

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