C. Streffer et al., MICRONUCLEI - BIOLOGICAL INDICATOR FOR RETROSPECTIVE DOSIMETRY AFTER EXPOSURE TO IONIZING-RADIATION, Mutation research. Fundamental and molecular mechanisms of mutagenesis, 404(1-2), 1998, pp. 101-105
Micronuclei can be measured through a conventional method after staini
ng with Giemsa or fluorescence dyes for DNA. However, a technique with
cell proliferation control should be preferred. This is done by incub
ation with cytochalasin B and counting the micronuclei in binucleated
cells. Satisfactory dose relationships are observed after irradiation
of human lymphocytes in vitro. The RBE for fast neutrons is around thr
ee. An automatic analysis is possible by image analysis. The dose rang
e in which significant increases can be observed is 0.3 to 5 Gy X-rays
. The assay becomes more sensitive when the micronuclei are determined
only in B-lymphocytes. Another possibility exists by determination of
the number of micronuclei with centromeres. For this purpose the hybr
idization with pancentromeric DNA probes and fluorescence labelling is
of advantage. By this technique a radiation dose of 0.1 Gy X-rays can
be detected. It is apparently also possible under these conditions to
detect radiation exposures which have taken place decades before the
measurements. (C) 1998 Elsevier Science B.V. All rights reserved.