5-Bromo-4-chloro-3-indolyl beta-D-glucopyranoside

5-bromo-4-chloro-3-indolyl beta-D-glucoside is an indolyl carbohydrate that is the beta-D-glucoside of 3-hydroxy-1H-indole in which the indole moiety is substituted at positions 4 and 5 by chlorine and bromine, respectively. It is used to test for the presence of an enzyme, beta-glucosidase, which cleaves the glycosidic bond to give 5-bromo-4-chloro-3-hydroxy-1H-indole, which immediately dimerises to give an intensely blue product. It has a role as a chromogenic compound. It is a beta-D-glucoside, an indolyl carbohydrate, an organochlorine compound, an organobromine compound and a D-aldohexose derivative. It is functionally related to an indoxyl.