ABSTRACT
In radiotherapy, alongside tumor control, the prevention of severe treatment-related side effects is a major concern. FISH applying one up to three whole-chromosome painting probes simultaneously was used to detect radiation-induced chromosome instability in peripheral blood lymphocytes and fibroblasts. FISH methods using all 24 human whole-chromosome painting probes simultaneously reach their limits in identification of intra-chromosomal rearrangements and when exact characterization of breakpoints is required. For detailed evaluation of each metaphase, it is not enough to rely only on the pseudocolor functions of the used software, but for unambiguous results, one has to check the different fluorochrome channels or hybridization profiles. Twenty-four-color FISH can be used as well as the three-color FISH. FISH is as reliable but more informative than conventional cytogenetic data.
