Used in bioorthogonal chemistry for labeling biomolecules in live cells without interfering with natural biological processes. Enables fluorescent imaging of cellular components through click chemistry reactions, especially copper-catalyzed azide-alkyne cycloaddition. Commonly applied in tracking nucleic acids, proteins, and glycans in molecular and cellular studies. Its near-infrared emission allows deep tissue imaging with low background fluorescence, making it valuable in advanced microscopy and in vivo imaging applications.