Fluorescence in situ hybridization (FISH) using whole-chromosome painting (wcp) probes has been shown to be a reliable technique for studying chromosomal changes. The three-color FISH method presented here is a simple and rapid assay that can be used for the detection of individual radiosensitivity. The individual chromosomal sensitivity is estimated after in vitro irradiation of only a limited amount of peripheral blood. By performing the three-color FISH approach, one is able to detect and quantify radiosensitivity on the one hand by quantifying the mis- and unrepaired break events, and on the other hand by scoring the frequency of translocations and complex aberrations. The three-color FISH method is described in detail, and results are provided that show the reliability of this approach.
