Used in bioimaging and fluorescence labeling due to its near-infrared emission, allowing deep tissue penetration and low background autofluorescence. Commonly conjugated to antibodies, peptides, or nucleic acids for in vivo imaging, tumor detection, and cellular tracking. The amine group enables easy coupling to carboxyl or activated ester groups in biomolecules. Suitable for applications in flow cytometry, microscopy, and molecular diagnostics where high sensitivity and minimal interference from biological matrices are required.