Effects of Cryopreservation on the Recovery of Radiation-Induced Chromosome Aberrations in Human Lymphocytes

Abstract

Experiments were conducted to determine whether irradiated blood samples may be preserved by freezing without compromising the accurate assessment of radiation-induced chromosome aberrations in lymphocyte cultures initiated at later dates. Human whole blood at 37 oC was exposed in vitro to 0, 1.2, or 4 Gy cobalt-60 gamma radiation, and lymphocytes were cultured immediately after exposure or after one weeks storage at -70 oC. A slight depression in cellular proliferation and a significant increase in chromatid breakages were observed in cultures initiated from the previously frozen lymphocytes. In preparations from both fresh and frozen lymphocytes the dose response relationships for radiation-induced dicentrics and acentrics were adequately described by the linear-quadratic dose response model (Y = aD + ßD2) with no significant differences in the values of the alpha or beta coefficients between the two sets of cultures. This finding provides evidence that lymphocytes bearing radiation-induced chromosome aberrations are not at selective risk for cell death as a result of cryopreservation.