Used as a chromogenic substrate in enzymatic assays, particularly for detecting esterase or lipase activity. When cleaved by the target enzyme, it releases 5-bromo-3-hydroxyindole, which oxidizes to form a blue-colored insoluble compound, enabling visual or spectrophotometric detection. Commonly employed in microbiological media and histochemical staining to identify enzyme-producing organisms or localize enzyme activity in tissues. Its long alkyl chain enhances membrane permeability and substrate specificity for lipolytic enzymes.