12th International Symposium on Bioluminescence & Chemiluminescence

Symposium abstracts:

Non invasive optical imaging of firefly luciferase gene expression in mice using the Berthold Technologies Nightowl LB 981

Coll, Jean-Luc¹, Favrot, Marie C.¹, Hennecke, Manfred²

1. INSERM EMI 9924, 38706 La Tronche, France

2. Berthold Technologies, 75312 Bad Wildbad, Germany

A549 lung carcinoma cells were transiently transfected in vitro with a pCMV-Luc plasmid. One day later the cells were resuspended and the level of luciferase was measured using a standard Luminometer assay. We determined that transfected cells expressed 3.9 10⁶ RLU/µl. A mixture containing 100 µl transfected cells and 100 µl Luciferin (Promega, 10 mg/ml in PBS) was injected subcutaneously in 4 different locations on the back of a nude mouse using 100 µl, 50 µl, 20 µl and less than 10 µl. The animal was immediately placed in the NightOWL light-tight chamber and gray-scale body-surfaces images were taken (0,2 s exposure time, 1x1 binning resolution level). Afterwards, photons emitted from firefly luminescence were acquired during one minute using a 5x5 pixel binning. A rectangle of 2745 pixel was then defined around each positive area, the software then provided the number of photons/s (the background photons were automatically removed from a negative area of the same size). Luciferase expression is observed in no more than 1 min of acquisition time. Quantification of the signal is possible and can be correlated directly with the in vitro measurement of luciferase. Correlation of in vivo CCD RLU versus in vitro Luminometer assays is r²=0,9531.

This is a preprint of an article accepted for publication in Luminescence: Copyright 2001 John
Wiley & Sons, Ltd (Wiley website)