A new system for analyzing the ionizing irradiation-induced chromosome abnormalities

Abstract

TThe analysis of chromosome aberrations in human peripheral blood lymphocytes is the most established method for the biological dosimetory of ionizing irradiation. Analysis of metaphase spreads with Giemsa staining, however, requires skilled person because of difficulty to identify abnormal chromosomes. FISH analysis of abnormal chromosomes makes it easy to identify chromosome abnormalities, but requires aging step for more than two days. Here, we established a FISH analysis using telomere and centromere PNA probes to obtain bright signals without aging for the analysis of abnormal chromosomes in the irradiated peripheral blood lymphocyte. Good agreement on the percentage of metaphases with dicentric chromosome after irradiation was observed between conventional Giemsa staining and FISH analysis. FISH detected more metaphase with multicentric chromosomes from lymphocytes irradiated at high dose than Giemsa staining analysis. Interestingly, percentage of metaphase with these complex abnormal chromosomes showed parallel increase with the irradiation dose. Since complex chromosome abnormalities could be missed by the analysis with Giemsa staining, the FISH technique may become a easy and reliable method for the biological dosimetory.