Scientists have created a bright red protein that can be used to tag and track cells and cellular processes. The breakthrough will aid stem-cell and cancer research.

Scientists have been using fluorescent proteins to track cells since the 1990s. The first tag was a green protein recovered from a fluorescent jellyfish. Researchers were able to tweak the protein to produce blue, turquoise and yellow tags.

Just more than a decade ago, researchers discovered a red protein in fluorescent coral, but try as they might, scientists have been unable to illuminate cells with it. To solve the problem, researchers at the University of Amsterdam decided to go the synthetic route.

Scientists teased the most essential bits of genetic code from a variety of fluorescent red coral species and stitched together their own DNA strand. They then tinkered with their novel code until they found a sequence that produced the brightest light.

They named their new highly fluorescent red protein mScarlet. After they were satisfied with their creation, researchers sent their protein to a group of scientists in France for further analysis.

“We discovered that mScarlet’s bright fluorescence is due to fact that the chromophore, the part of the molecule that absorbs light and then emits red light, is held rigidly flat by the protein wrapped around it,” said Antoine Royant, a researcher at France’s Institute of Structural Biology.

Scientists hope their new protein — described this week in the journal Nature Methods — will advance cancer research and other disease studies. The more color proteins scientists have at their disposal, the greater the number of cells they can track simultaneously.

“Just as other people study the stars and prepare future trips to Mars, we are exploring the universe of the proteins that regulate the cellular processes within our bodies,” said molecular biologist Dorus Gadella.