What are the most commonly used luciferase enzymes?

Luciferases are enzymes that produce light when they oxidize their substrate. The most common types of luciferase enzyme are firefly, Renilla and Gaussia. Firefly luciferase (FLuc) is perhaps the most well-known, well-studied, and widely-used of all the luciferases. Firefly luciferase uses luciferin as a substrate, oxidizing it to oxyluciferin in a reaction that utilizes molecular oxygen and ATP, and produces light at 560 nm. Renilla luciferase (RLuc) is another commonly used bioluminescent reporter. RLuc uses coelenterazine as its substrate. The RLuc bioluminescent reaction does not require ATP. It is significantly less efficient than FLuc. Gaussia luciferase (GLuc) is the smallest known luciferase. The same as RLuc, GLuc catalyzes uses coelenterazine as a substrate and does not require ATP for functionality. It produces primarily blue light, with a peak emission wavelength of 480 nm. GLuc is one of the brightest luciferases. However, unlike FLuc and RLuc, the GLuc protein is naturally secreted from the cells. In biotechnological applications, this allows signal measurements to be performed on culture medium without cell lysis and when using blood or urine samples obtained during animal applications.