Kusabira-Orange is an orange fluorescent protein with an excitation peak of 548nm and an emission peak of 561nm in vitro. It is an artificial derivative of a cDNA clone (GenBank AB128819; BAD24720) isolated from the Verrillofungia concinna stony coral, generated by adding an artificial amino acid sequence (MSVIKPE) to the N-terminal end of the cDNA coding sequence (PMID:15065984).