Until now the greatest limitation in the application of bioactive compounds has been the inability of confining them specifically to single cells or subcellular components within the organism. Our recently synthesized photoactive forms of bioactive compounds solve this problem. We have developed effective chemical synthesis methods to attach an azide group to small drug-like molecules, which makes them photoactive. As a result, light irradiation can induce the covalent attachment of these molecules to their target enzymes. By controlling the timing and position of light irradiation it is possible to confine the effect of these molecules in time and space. It is important to emphasize that azidation is the smallest possible modification (adding 3 nitrogen atoms) that makes a compound photoactive and based on our experience it does not alter biological activities of most of the original compounds.Azidated inhibitors give unprecedented freedom to researchers because the covalent compound-target formations allow them to address questions which could not have been addressed before. Three major advantages are obtained by using azidated compounds 1: determination of small molecule interactome becomes highly effective, especially, the weak interactions can be determined, which was not possible before 2: it improves the pharmacodynamic and pharmacokinetic properties of biological compounds as the covalent attachment prolongs their effect. 3: Recently, we showed that photoactivation can be initiated by two-photon excitation, thereby confining the effect to femtoliter volumes and well-controlled spatial locations. This feature provides unprecedented spatial and temporal control in localizing the effect of biological compounds in cellular and subcelluler level in in vivo experiments. By realizing the need for photoactive compounds, the PI has established Drugmotif Ltd., a spin-off company, which provides the customers with special azidated chemicals for high-tech research.