Coelenterazine 400a, also called DeepBlueC™, is a coelenterazine derivative that serves as a substrate for Renilla luciferase (Rluc) and generates an emission peak centered around 400 nm. It is the preferred Rluc substrate for BRET studies because it has minimal interference with the emission of the GFP acceptor. Properties : Off-white to pinkish solid soluble in MeOH or EtOH; Store at -20°C, protect from light; C26H21N3O; MW: 391.46. DeepBlueC is a trademark of BioSignal Packard.