Roper Scientific's cooled, high-performance CCD cameras are routinely used for fluorescence in situ hybridization (FISH) applications such as whole-chromosome painting, locus-specific analysis, gene mapping, and comparative genomic hybridization (CGH).
CCD cameras are used primarily because of their ability to "see" beyond the capabilities of the human eye. Visualization of small cDNA clones, CGH experiments, and combinatorially labeled probes all require low-light sensitivity. Specifically, cameras are optically coupled to the microscope such that the pixel-to-pixel resolution matches that of the microscope optics. Gene mapping is therefore limited by the theoretical resolution limit, not by the imaging device. Finally, the linear fashion in which light intensities are converted allows accurate distribution determination in CGH, precise probe distinction during combinatorial labeling, and detection of weak signals over large backgrounds typical of probes under 1 kilobase in size.