5-Bromo-4-chloro-3-indolyl b-D-xylopyranoside is an enzyme substrate. This chromogenic substrate is used for beta-D-xylosidase enzyme. In culture media, 5-Bromo-4-chloro-3-indolyl b-D-xylopyranoside is utilised for identification of bacteria such as Klebsiella and Enterobacter.