Lluciferin

Lluciferin is not a widely recognized chemical name in bioluminescence literature. The term is sometimes encountered as a misspelling or informal reference to luciferin, or more specifically to the enantiomer known as L-luciferin. In standard bioluminescence, the substrate used by firefly luciferase is D-luciferin.

D-luciferin is consumed in a reaction catalyzed by luciferase in the presence of ATP, magnesium ions, and oxygen, producing oxyluciferin and visible light, typically in the yellow to green part of the spectrum. This reaction is the basis for many bioluminescence assays and imaging techniques in molecular biology, cell biology, and medicine. Luciferin compounds are produced by various organisms and come in several structural classes, with D-luciferin being the most widely used in firefly-based systems.

L-luciferin, the mirror image enantiomer of D-luciferin, is not efficiently utilized by most native luciferases and generally yields little or no light in standard firefly reactions. Research in bioluminescence has explored alternative luciferases and synthetic analogues that can recognize or respond to enantiomeric substrates, but such systems are specialized and not as common as the conventional D-luciferin–luciferase pair.

Applications of luciferin in general include in vivo and in vitro imaging, reporter assays, and gene expression studies, where real-time, noninvasive light emission serves as a readout. Safety and handling follow typical laboratory practices for chemical reagents and biological materials. See also luciferase, bioluminescence, D-luciferin, and L-luciferin.