|This is an example of the luminescence produced by the |
chemical modifications described in this article. Key: -S,
a tube without streptavidin; +S, with streptavidin.
(Credit: Kai Johnsson/EPFL)
In biology and medicine, we often need to detect biological molecules. For example, in cancer diagnostics, doctors need quick and reliable ways of knowing if tumor cells are present in the patient's body. Although such detection methods exist, they often require a lot of time, work and money.
Now, researchers have chemically tweaked the enzyme responsible for the light of fireflies to make it "sniff out" target biological molecules and give out a light signal. The result is a cheap, simple and highly accurate detection system that can change the face of the field. The work is published in Nature Communications.
The researchers were able to add a small chemical tag on the enzyme luciferase, which produces the light of fireflies. The tag detects a target protein, and the luciferase gives out a light signal that can be seen with a naked eye.
The tag acts as a switch: it blocks luciferase, 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 turn on the lights, which is the signal that the target has been found. In short, the scientists have created a chemical solution for a biological problem.
The activation of luciferase when it detects its target protein is dramatic enough to see with a naked eye. This means that the system does not demand expensive and complicated readout devices.
Based on material originally posted by Ecole Polytechnique Fédérale de Lausanne.