Varieties of FishAfter hybridization, electronic imaging systems are used to capture and quantify the relative fluorescence intensities of each of the hybridized fluorophores. The ensuing ratio of the fluorescence intensities is proportional to the ratio of the copy numbers of DNA sequences in the test and reference genomes. If the intensities of the fluorochromes are equal on one probe, this region of the affected person’s genome is interpreted as having equal quantity of DNA in the test and reference samples; if there is an altered Cy3:Cy5 ratio, this suggests a loss or a gain of the affected person DNA at that real genomic region Taken from omparative genomic hybridization/media/File:Array CGH protocol. svgFISH has now become an a must-have tool for gene mapping and characterization of chromosome aberrations. Since the objective DNA remains intact, unlike in molecular genetic evaluation, tips is bought at once about the positions of probes relating to chromosome bands or to other hybridized probes. Using differentially categorized probes, chromosome aberrations on specific chromosomes or chromosomal regions can be easily defined.