Used in bioimaging and fluorescence labeling due to its near-infrared emission, enabling deep tissue visualization with low autofluorescence. Commonly conjugated to biomolecules like antibodies, peptides, or nucleic acids for detection in assays such as flow cytometry, microscopy, and in vivo imaging. The carboxylic acid group allows easy coupling to amine-containing compounds using standard crosslinking chemistry like EDC/NHS activation. Ideal for tracking biological processes in real time and developing diagnostic probes.