NanoLuc is an engineered luciferase derived by mutagenesis of the small (19KDa) subunit (GB:AB030246) of the luciferase from Oplophorus gracilirostris. When used with furimazine, an optimized substrate, NanoLuc produces a high-intensity glow-type luminescence with a specific activity approximately 150 times greater than that of either pLUC or rLUC (PMID:22894855, reviewed in PMID:27045664).