3-Indolyl b-D-glucuronide sodium salt is a specialized enzyme substrate that features an indole moiety linked to a glucuronide group. This compound is commonly used in various biochemical assays to study the activity of glucuronidase enzymes, which play a crucial role in the metabolism and detoxification of xenobiotics and endogenous compounds. The sodium salt form of this substrate ensures enhanced solubility and stability in aqueous solutions, making it a valuable tool for researchers investigating the function and regulation of glucuronidase enzymes in biological systems. 3-Indolyl b-D-glucuronide sodium salt is also used for the detection of E. coli.