4-Azidocoumarin is widely used in biochemical and biomedical research due to its photoactive properties. It serves as a photoaffinity labeling agent, enabling the study of protein-ligand interactions by forming covalent bonds with target molecules upon UV light exposure. This property is particularly useful in identifying binding sites and understanding molecular mechanisms in complex biological systems. Additionally, it is employed in the development of fluorescent probes for imaging and tracking biological processes in live cells. Its azide group also allows for click chemistry applications, facilitating the conjugation of biomolecules for various diagnostic and therapeutic purposes.