Because detecting biological molecules for medical diagnostic work is an expensive process, Swiss researchers at EPFL set out to find a more economically viable solution. Their goal led them to chemically tweak luciferase, the enzyme responsible for the light of fireflies, to make it target biological molecules and emit a light signal. In addition to proving inexpensive, the technique is also simple and highly accurate at detecting its target, thus positioning it to potentially make significant changes in the practice of medical diagnostics.
Sidestepping conventional methods, the team decided not to mutate the luciferase to make it sensitive for a target protein—which would require enormous work—but instead simply attached a small chemical tag. The tag acts as a switch, blocking luciferase and preventing it from producing light. When the tag detects its target protein, it attaches to that instead, removing the block from lucifarase. As a result, luciferase is free to switch on the light signal, indicating that the target has been found. Because the signal can be seen with the naked eye, it does not require expensive or complicated readout devices.