Description_x000D_ General description_x000D_ D-Luciferin is mainly produced in bioluminescent organisms. It can simply circulate across the blood testis barrier, blood brain barrier and the blood placenta barrier. This small molecule is sensitive to light and oxygen. D-Luciferin is also sensitive to moisture in its powder form._x000D_ Application_x000D_ D-Luciferin sodium salt has been used as a substrate in luciferin−luciferase chemiluminescence assay to determine ATP levels._x000D_ Substrate for firefly luciferase with a Km of approx 2 μM.