Firefly luciferase has been used as a sensitive reporter for studying gene regulation and function. Luciferase provides a 1000-fold increase in sensitivity in comparison to the standard chloramphenicol acetyltransferase (CAT) assay. Firefly luciferase catalyzes the oxidative carboxylation of luciferin, a reaction with the highest efficiency of any known bioluminescence reaction. The light emission from the reaction can be recorded using a luminometer. BioVision's Luciferase Reporter Assay Kit provides a simple means for detecting luciferase activity in transfected eukaryotic cells. For measurement of expressed luciferase in vitro, luciferase is first extracted from transfected cells through cell lysis. Then CoA, ATP, Mg2+ and buffer are add