This chemical is widely used in bioorthogonal chemistry for labeling biomolecules. It reacts efficiently with strained alkenes or alkynes via inverse electron-demand Diels-Alder (IEDDA) reactions, enabling rapid and selective conjugation. It is particularly useful in live-cell imaging and protein labeling due to its water solubility and biocompatibility. The sulfo-NHS ester group allows for specific covalent attachment to primary amines, making it ideal for modifying peptides, proteins, or antibodies. Its applications extend to drug delivery systems, diagnostics, and the development of targeted therapies, where precise and efficient labeling is critical.