Used primarily as a photoactivatable crosslinking agent in biochemical and molecular biology research. It enables covalent bonding between biomolecules upon exposure to UV light, making it valuable for studying protein-protein, protein-nucleic acid, and ligand-receptor interactions. The diazirine group generates reactive carbenes when photoactivated, which insert nonspecifically into nearby C–H, N–H, or O–H bonds, forming stable crosslinks. The alkyne handle allows for downstream conjugation via click chemistry, facilitating detection, purification, or immobilization of crosslinked complexes. The 4-nitrophenyl carbonate moiety serves as a reactive group for conjugation to biomolecules such as proteins or ligands prior to photoactivation. Commonly applied in photoaffinity labeling to map binding sites and identify interaction partners in complex biological systems.