Red Russian Katushka

For deep imaging of animal tissues, the optical window favorable for light penetration is in near-infrared wavelengths, which requires proteins with emission spectra in the far-red wavelengths. In the 4th issue of Nature Methods, the journal that publish significant improvements to tried-and-tested techniques in the life sciences, Dmitry Shcherbo and colleagues from Moscow University, report a far-red fluorescent protein, named Katushka, which is brighter compared to the spectrally close HcRed or mPlum, and is characterized by fast maturation as well as a high pH-stability and photostability.
These unique characteristics should make Katushka a good reporter for visualization in living tissues. A monomeric version of Katushka, named mKate, was also generated: mKate is characterized by high brightness and photostability, and should be an excellent fluorescent label for protein tagging in the far-red part of the spectrum.