Used as a fluorescent labeling agent in biological imaging and immunohistochemistry. Its high quantum yield and photostability make it ideal for detecting proteins, nucleic acids, and cellular structures under fluorescence microscopy. Commonly conjugated to antibodies or streptavidin for use in fluorescence-based assays such as ELISA, flow cytometry, and multiplex labeling. Also employed in fixed-cell and fixed-tissue imaging due to its strong blue fluorescence and compatibility with common microscope filter sets.