 Renilla luciferase

A luminescent reporter enzyme often used as a separately measured reference in a dual-luciferase assay. Valid normalization requires a reference insensitive to the experimental manipulation.

Its reaction oxidizes coelenterazine using oxygen and differs chemically from the ATP-dependent firefly system. Using a distinct reaction permits separate optical readouts, but substrate availability and enzyme behaviour still need to be considered when comparing signals. ^[ref]