Widely used in immunohistochemistry and enzyme-linked assays as a chromogenic substrate for alkaline phosphatase detection. Upon enzymatic dephosphorylation, it forms an insoluble blue-purple precipitate at the reaction site, enabling visualization of target antigens in tissue sections and blots. Its high sensitivity and low background make it suitable for diagnostic staining and research applications in cellular and molecular biology. Commonly applied in combination with other substrates for multiplex staining techniques.