AmCyan has been adapted from the corresponding full length cDNA for higher solubility, brighter emission, and rapid chromophore maturation. AmCyan1 has been human-codon optimized for enhanced translation in mammalian cells. AmCyan is a very good blue fluorescent reporter protein, and useful in two-color analyses with DsRed2, DsRed-Express, or AsRed2, and in three-color analyses with ZsYellow and HcRed.