A quantitative analysis of radiation-induced chromosome aberrations with a fluorescent digital image microscope.
Using a synthetic, alpha satellite consensus DNA unit as a probe, we could show dicentrics as well as acentric fragmented chromosomes in metaphases of gamma-irradiated lymphocyte cells and that the number of appearance of dicentrics or acentric fragments seemed to be proportional to radiation doses. To make such examination with a large number of chromosomes of metaphases, a quantitative fluorescence measurement was performed using a fluorescent microscope digital image analysis system. The relative amounts of fluoresceinated probe hybridized to alpha satellite DNA varied with chromosomes to a certain extent (1-4% of total probe-fluorescence of one metaphase). However, we could score dicentrics and acentric fragments as dots with extraordinarily higher or low percentage in plots of relative amount of probe-fluorescence on metaphase chromosome in gamma-irradiated cells. The number of appearance of acentric fragments were proportional to radiation doses of 1, 2 and 4 Gy. In the case of dicentrics, the number of appearance seemed to be proportional to square doses. Further, to reduce the variation of relative amounts of probe-fluorescence, we tried to make probe-fluorescence reflect the content of alpha satellite DNA on each chromosome more exactly, using a DNA probe amplified by polymerase chain reaction.
Kameoka
Y
Y
National Institute of Health, Tokyo, Japan.
Hirata
M
M
Goto
E
E
Deng
L R
LR
Maekawa
H
H
Hashimoto
K
K
D002869:Chromosome Aberrations / Q000235:genetics*; D002875:Chromosomes / Q000528:radiation effects*; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects / Q000648:ultrastructure; D008297:Male; D008856:Microscopy, Fluorescence / Q000295:instrumentation; D011874:Radiometry / Q000379:methods*