For noninvasive in vivo optical imaging
Firefly luciferase (Fluc, Luc2), initially isolated from the firefly Photinus pyralis, is an enzyme that catalyzes the oxygenation of d-luciferin to oxyluciferin, producing visible light (530-640 nm). Several generations of Fluc have been engineered, each improving brightness. Unless otherwise specified, Imanis Fluc products have the Luc2 version of the protein (footnote), a highly optimized variant with exceptional brightness.
The bioluminescence produced by Fluc facilitates noninvasive optical imaging following the administration of d-luciferin.
How to use Luciferase for imaging
Equipment: An optical imager equipped with cooled CCD cameras can be used to detect the light produced by the oxidation of d-luciferin. The acquired bioluminescent image can be overlayed with a photograph taken by the optical imager to show the relative location of the bioluminescent signal.
Additional considerations: Bioluminescence peaks about 10-12 min after the administration of d-luciferin and slowly drops.
When to use luciferase
Bioluminescent imaging with Fluc can be used to noninvasively track the biodistribution of cells or viruses in pre-clinical regenerative medicine, gene therapy, oncology, and oncolytic virotherapy studies. Background bioluminescence of tissues is very low, so Fluc imaging has a very good signal to background ratio and excellent sensitivity in mice and other small animals, where the signal is relatively close (1-2 cm) to the surface of the animal. Thus, Fluc imaging is ideal for studies requiring the detection of a low number of cells or viruses. D-luciferin readily crosses the blood brain barrier, so Fluc can be used for imaging in the brain and CNS.