Comparison of stable and unstable chromosome aberrations induced by X-rays in human lymphocytes

Relationship between stable and unstable lymphocytic chromosome aberration of M1-cells induced with doses of 0.56, 1.12 and 1.68 Gy of X-rays in vitron was studeid with G-banding technique. It was shown that the ratio of stable to unstable chromosome aberrations was 1. The relationship between thses two categories of chromosome aberrations and doses was well fitted to linear quadratic equations. In the culture time from 41 to 72 hours the stable chromosome aberrations did not change obviously while unstable chromosome aberrations decreased significantly with a loss rate of 47.3 per cent. Either the breakage points in each irradiated group or the total breakage points exhibited non-random distribution