COMPARISON OF GAMMA-RAY INDUCED DICENTRIC YIELDS IN HUMAN-LYMPHOCYTESMEASURED BY CONVENTIONAL ANALYSIS AND FISH

In an earlier work stable aberrations and dicentrics were determined b y fluorescence in situ hybridization (FISH) after various doses of Cs- 137 gamma-rays. No corresponding calibration curve for dicentrics is a vailable for determinations in terms of the conventional analysis as p erformed in our laboratory. In view of the potential for the applicati on of chromosome painting to human biological dosimetry, it is desirab le to determine such a calibration curve and this and the comparison o f the resulting data to those obtained in terms of the FISH method is the objective of the present communication. In the study it is found t hat the linear-quadratic dose response curves for dicentrics, that are determined by the two methods, are significantly different, although the different target sizes are accounted for. A similar problem was fo und earlier for X-rays. It does not appear that the difference is due to technical difficulties in the FISH method, that has been improved b y employing in addition to the whole chromosome DNA probes, a pan-cent romeric DNA probe.