Used in bioconjugation for labeling and crosslinking biomolecules under mild aqueous conditions. Its DBCO group reacts rapidly and selectively with azides via copper-free click chemistry, making it ideal for live cell labeling without cytotoxic effects. The sulfo-NHS ester reacts efficiently with primary amines on proteins, antibodies, or amine-modified nucleic acids to form stable amide bonds. Commonly applied in preparing fluorescent probes, drug conjugates, and functionalizing surfaces in diagnostic and therapeutic research. Water solubility from the sulfo group eliminates the need for organic solvents, enabling direct use in biological buffers.