Used as a fluorescent probe in biological imaging due to its strong near-infrared (NIR) emission. Enables deep tissue visualization with minimal background interference, making it suitable for in vivo imaging and real-time monitoring of cellular processes. Its sulfonate groups enhance water solubility and reduce nonspecific binding, improving signal clarity in complex biological environments. Commonly employed in fluorescence microscopy and flow cytometry for labeling and tracking biomolecules, particularly in cancer research and immunology. Also utilized in diagnostic assays where high sensitivity and low photobleaching are required.