Used as a fluorescent dye in biological imaging and labeling applications. Its high photostability and bright emission make it suitable for tracking biomolecules in live cells. Commonly conjugated to antibodies, peptides, or nucleic acids for use in fluorescence microscopy, flow cytometry, and immunoassays. The carboxylic acid group allows for easy covalent attachment to amine-containing molecules using standard coupling chemistry. Exhibits strong absorption and emission in the visible range, enabling clear detection with minimal background interference. Ideal for multiplexing due to its distinct spectral properties.