Cerulean is a cyan fluorescent protein with an excitation peak of 433nm and an emission peak of 475nm in vitro. It is an artificial derivative of the naturally occurring fluorescent protein encoded by the Aequorea victoria GFP gene (UniProtKB:P42212), derived by mutagenesis of ECFP, and its fluorescent properties make it useful as a FRET donor. It contains the mutations F64L, S65T, Y66W, S72A, Y145A, N146I, H148D, M153T, V163A relative to the wild-type GFP sequence (PMID:14990965).
