The BioLux® Gaussia Luciferase Assay Kit contains the reagents necessary for assaying Gaussia Luciferase (GLuc) activity, most commonly from cell culture supernatants. Gaussia Luciferase is a reporter luciferase from the marine copepod Gaussia princeps (1,2). Gaussia Luciferase can be expressed in mammalian cells using reporter plasmids available from NEB (Refer to the Companion Products). This luciferase, which does not require ATP, catalyzes the oxidation of the substrate coelenterazine in a reaction that produces light (Figure 1), and has considerable advantages over other luminescent reporter genes.