D-Luciferin is a substrate for the enzyme firefly luciferase. Chemiluminescence at 560 nm is generated when luciferin is oxidized by an ATP-dependent process, catalyzed by luciferase. Luciferase is encoded by the <i>luc</i> gene, which is widely used as a reporter gene in a variety of cells. Because of the intrinsic low background of chemiluminescence technique, detection of the luc gene expression can be made at very low level. In addition, luciferin/luciferase has been used to measure 10^-15 molar quantity of ATP. D-luciferin, sodium salt is a water-soluble form of D-luciferin.<ul><li>White solid soluble in water</li><li>Store at -20&deg;C and protect from light</li><li>C₁₁H₇N₂NaO₃S₂.H₂O</li><li>Mwt: 302.3</li><li>[103404-75-7]</li></ul>