After being exposed to laser radiation at a particular wavelength, some proteins emit light at a different wavelength.
This induced "glow" can be analysed using a special microscope.
Researchers said the protein holds prospects for fluorescence microscopy, a technique used in research on cancer, infectious diseases, and organ development, among other things.
In the journal Photochemical & Photobiological Sciences, researchers append such fluorescent proteins to other proteins via genetic engineering to make the latter ones visible to the microscope and observe their behaviour in cells.
Until now, the fluorescent proteins used for such observations had several flaws. They were vulnerable to heat, fairly bulky, and only glowed in the presence of oxygen, researchers said.
"For one thing, our protein is more thermostable than its analogues: It only denaturates at 68 degrees Celsius," said Vera Nazarenko from MIPT.
"It is also miniature, while most of the currently used fluorescent proteins are rather bulky. On top of that, it can emit light in the absence of oxygen," Nazarenko said.
The team originally identified the protein with these remarkable properties in the cells of a thermophilic bacterium -- one which lives in high-temperature environments, such as hot springs.
The researchers then genetically engineered a DNA sequence that reproduced the protein's fluorescent segment but not the other parts, which would make the molecule larger.
By introducing the gene that encodes the protein into the cells of another bacterium, Escherichia coli, the team turned it into a factory mass-producing the fluorescent protein with unique properties.
Researchers studying the processes that occur in living cells have been waiting for a protein combining these crucial features for a long time.
By introducing it into cells, they can now obtain essential data on cell life and death.
Fluorescence microscopy is seen as one of the best tools for investigating the mechanism behind malignant tumour genesis and development, researchers said.
It is also useful for research on cell signalling and organ development, they said.