Absence of an effect of diagnostic ultrasound on sister-chromatid exchange induction in human lymphocytes in vitro.

The frequency of sister-chromatid exchanges in human lymphocytes cultured in vitro was not changed after a 30-min exposure to a 2 MHz focused, diagnostic ultrasound beam with a pulse repetition rate of 1000 Hz, 1 musec burst duration, 100 W/cm2 temporal peak, spatial peak intensity. These results are consistent with those obtained with a number of other cell types and are contrary to some previously reported effects for human lymphocytes.