The use of FISH chromosome painting for assessment of old doses of ionising radiation

This paper critically reviews data obtained at NRPB concerning the use of FISH chromosome painting for biological dosimetry purposes. Most of the work has aimed at investigating how persistent translocations are with time and this has influenced the choice of aberration which should be used to set up calibration curves. Chromosomes 2, 3 and 5 and all centromeres were painted and the observed translocations classified as one-way or two-way. Two-way translocations appear stable with time whereas one-way translocations decrease by possibly a factor of 2. Since two-way translocations outnumber one-way translocation by about 1.5 to 1, total translocation yields reduce by only about 20% with time. To make use of total translocation yield for biological dosimetry purposes, calibration curves should be constructed from the measurement of translocations in stable cells only. (author)