Widely used in microbiology and molecular biology as a chromogenic substrate for the detection of β-glucuronidase (GUS) enzyme activity. Its primary application is in the identification and enumeration of pathogenic bacteria such as Escherichia coli, especially E. coli O157:H7, in food, water, and clinical samples. When cleaved by β-glucuronidase, it releases a fluorescent and chromogenic product that allows for easy visual or instrumental detection. It is also employed in gene expression studies, particularly in transgenic plants where the GUS reporter gene system is used to monitor promoter activity. The compound enables rapid, sensitive, and selective assays in both qualitative and quantitative formats.