The effects of ß-radiation on sister-chromatid exchanges in cultured human lymphocytes

Abstract

The incidence of Sister-Chromatid Exchanges (SCEs) due to ß-radiation was investigated in cultured human lymphocytes using the BrdU/Giemsa technique. Cultures treated continuously with 0.001 and 0.01 μCi of [ 3H] uridine showed no increase in either chromosome abrnomalities or SCEs. Continuous treatment with 0.1 μCi resulted in a significant increase in chromosome aberrations but no increase in SCEs, while treatment with 0.2 μCi gave both an increase in chromosome aberrations and SCEs. Cultures given a 4-h pulse with 1.0 μCi showed a significant increase in both SCEs and chromosome aberrations. The results indicate that low level of ß-radiation do not cause and increase in SCEs in human lymphocytes, and, that a number, if not all the exchanges observed at low levels of ß-radiation with autoradiography, may be spontaneous events.