Primarily used in histochemistry and cytochemistry as a substrate for the detection of alkaline phosphatase activity. When hydrolyzed by the enzyme, it releases a naphthol derivative that couples with a diazonium salt to form a colored precipitate, aiding in the visualization of enzyme localization in tissue sections. This application is crucial in diagnostic pathology for identifying cellular and tissue abnormalities. Additionally, it is employed in research to study enzyme distribution and activity in various biological samples.