4-Nitrophenyl 2-O-(b-D-glucopyranosyl)-b-D-glucopyranoside is a bioluminescence substrate that is used in the detection of hexokinase. It can be used as a chromogenic substrate for the detection of ?-galactosidase, ?-glucuronidase, ?-mannosidase, and ?-fucosidase activities. 4NP2BG can also be used to detect phosphatases and esterases with its fluorescence properties. 4NP2BG has a CAS number of 16790-33-3 and is a fluorogenic substrate for chemical luminescence.