The Xenogen IVIS-200 System is capable of imaging bioluminescence and fluorescence in living animals. A light-tight imaging chamber is coupled to a highly-sensitive CCD camera system cooled to -95°C. This camera system is capable of quantitating single-photon signals originating within the tissue of living mice. Up to five mice can be imaged simultaneously and an integrated isoflurane gas manifold allows rapid and temporary anesthesia of mice for imaging.
Bioluminescence from cell lines expressing firefly luciferase remains the most sensitive method for optical detection. The emission spectrum of luciferase at 37°C is largely above 600nm, and penetrates tissue very efficiently. Since excitation light is not required for luciferase bioluminescence, there is also minimal autofluorescence. For investigators interested in establishing luciferase-expressing cell lines for imaging, we recommend the pGL4 luciferase expression vector from Promega. The pGL4 plasmid is optimized for mammalian codon usage and routinely yields higher luciferase activities than other luciferase expression vectors.