BCIP p-toluidine salt is widely used in molecular biology and biochemistry as a substrate for alkaline phosphatase in various detection assays. It is particularly valuable in techniques like Western blotting, ELISA, and immunohistochemistry, where it helps visualize proteins or nucleic acids. When cleaved by alkaline phosphatase, it produces an insoluble indigo dye, which forms a blue precipitate, allowing for precise localization of target molecules. This property makes it a crucial tool in research labs for studying protein expression, cellular localization, and diagnostic applications. Its sensitivity and reliability contribute to its widespread use in both academic and clinical settings.