Used as a substrate in enzymatic assays to measure β-glucuronidase activity. Upon hydrolysis by the enzyme, it releases 4-nitrophenol, which produces a yellow color detectable spectrophotometrically (typically at 405 nm), enabling precise quantification of enzyme activity. This is essential in biochemical research, clinical diagnostics, and pharmaceutical development. It facilitates detection of enzyme activity in biological samples, studies of enzyme kinetics, and screening of inhibitors. Additionally, it is utilized in diagnostic kits for detecting bacterial contamination, as β-glucuronidase serves as a marker for certain bacteria like E. coli. In pharmaceutical research, it supports evaluation of drug metabolism, particularly glucuronidation processes.