SuperNova-Red is a monomeric red fluorescent protein with an excitation peak of 579nm and an emission peak of 610nm. SuperNova-Red acts as a genetically encoded photosensitizer; upon exposure to intense orange light it generates reactive oxygen species (predominantly superoxide). This property can be used to selectively inactivate a protein of interest in living cells, using the chromophore-assisted light inactivation (CALI) technique; in this case SuperNova-Red is fused to a protein of interest, and upon intense light illumination, the reactive oxygen species produced can disrupt the function of this protein by oxidizing susceptible amino acid residues. SuperNova-Red was derived by mutagenesis of KillerRed, containing the amino acid substitutions G3V, N145S, L160T, F162T, L172K and M204T relative to KillerRed (PMID:24043132).