TagRFP is a monomeric red fluorescent protein with an excitation peak of 555nm and an emission peak of 584nm in vitro. It is an artificial derivative of the naturally occurring fluorescent protein encoded by the Entacmaea quadricolor eqFP578 gene. TagRFP is characterized by high brightness, complete chromophore maturation, prolonged fluorescence lifetime and high pH-stability (PMID:17572680).