Fast Red B Salt 1,5-Naphthalenedisulfonate is widely used in biochemical research as a chromogenic substrate for detecting alkaline phosphatase activity. It is commonly employed in immunohistochemistry and in situ hybridization techniques to localize specific proteins or nucleic acids within tissue samples. When applied, it produces a red precipitate upon enzymatic reaction, allowing for clear visualization under a microscope. This makes it a valuable tool for studying cellular and molecular processes in biological samples. Additionally, it is utilized in ELISA assays for the detection of target molecules, providing a reliable and sensitive method for quantitative analysis in research and diagnostic applications.