Comparison of X-ray dose-response curves obtained by chromosome painting using conventional and PAINT nomenclatures

Purpose: The compare the suitability of PAINT and conventional nomenclature systems for the construction of chromosome aberration dose-effect curves f or X-rays using FISH techniques, and to compare these curves with those bas ed on solid-stained dicentrics analysed in first division metaphases by the FPG technique. Materials and methods: Blood samples were irradiated at 0.1, 0.25, 0.50, 0. 75, 1, 1.5, 2, 3, 4 and 5 Gy 180 kV X-rays. FISH painting was performed usi ng probes for chromosomes 1, 4 and 11 in combination with a pan-centromeric probe. Results: Translocations showed a higher background frequency than dicentric s. This influences the ratio of translocations:dicentrics at the lower dose s and the uncertainties of dose-effect curves for translocations. The dose- effect curves for dicentrics obtained by FISH and solid stain were in close agreement. Conclusion: For short-term biological dosimetry purposes by FISH, the use o f dic(BA) (PAINT nomenclature) or total dicentrics (conventional nomenclatu re) should give similar dose estimates. For dose reconstruction, the use of total or complete translocations result in similar uncertainties.