4-Methylumbelliferyl b-D-celloheptaoside is a fluorogenic substrate that can be used for the detection of ?-glucuronidase activity in biological fluids. This compound is an enzyme substrate that is used in various diagnostic applications, such as the detection of ?-glucuronidase activity in culture media, chemiluminescence, and bioluminescence. 4-Methylumbelliferyl b-D-celloheptaoside is also used to detect ?-glucuronidase enzyme activity in food samples. The reactivity of this compound can be enhanced by addition of a chromogenic substrate to produce a blue color.