5-Bromo-4-chloro-3-indolyl phosphate (BCIP, X-phosphate, XP) is an artificial chromogenic substrate used for the sensitive colorimetric detection of alkaline phosphatase activity. It is, for example, used in immunoblotting, in situ hybridization, and immunohistochemistry, often in combination with nitro blue tetrazolium chloride (NBT). 5-bromo-4-chloro-3-indoxyl is oxidized by atmospheric oxygen to form the blue dye 5,5′-dibromo-4,4′-dichloro-indigo. It is also oxidized by nitroblue tetrazolium (NBT), which forms an insoluble dark blue diformazan precipitate after reduction. Alkaline phosphatase is commonly conjugated to secondary antibodies.

CAS：38404-93-2
中文别名：
英文别名：5-bromo-4-chloroindoxyl phosphate;5-Bromo-4-chloro-3-indolyl phosphate;Fragment compound,6;Indole der.;5-Bcip;BCIP;5-Bromo-4-chloro-3-indoxyl phosphate;(5-bromo-4-chloro-1H-indol-3-yl) dihydrogen phosphate;
分子式：C8H6BrClNO4P
分子量：326.468
精确质量：324.891
Psa：92.36
Logp：3.0553

密度：2.083 g/cm3
沸点：580.2ºC at 760 mmHg
闪点：304.7ºC

海关编码：2933990090