Used as a fluorescent dye in biomedical imaging and labeling applications. Its strong fluorescence and water solubility make it suitable for conjugation with proteins, antibodies, or other biomolecules for use in fluorescence microscopy, flow cytometry, and immunoassays. The sulfonate groups enhance solubility and reduce nonspecific binding in biological systems. Commonly employed in tracking cellular components and monitoring molecular interactions in live or fixed cells. Also utilized in diagnostic kits and high-sensitivity detection methods due to its stable and bright signal output.