mScarlet-I is a monomeric red fluorescent protein with an excitation peak of 569nm and an emission peak of 593nm in vitro. It is an artificial fluorescent protein, derived by mutagenesis of a synthetic gene template ('mRed7') that was designed based on mCherry, several naturally occurring red fluorescent proteins and chromoprotein structural information. mScarlet-I has high brightness and shows fast maturation. It is especially useful as a fluorescence resonance energy transfer (FRET) acceptor in ratiometric imaging (PMID:27869816).
