Rapid estimation of the duration of gamma-ray-induced proliferation delay in human lymphocytes by the harlequin staining technique.

The duration of gamma-ray-induced proliferation delay in human lymphocyte cultures was measured by a rapid and simple method using fluorescence-plus-Giemsa (harlequin) staining to distinguish between cells that had divided different numbers of times in culture. By this rapid method, irradiation of unstimulated (G0) or stimulated (G1) lymphocytes was shown to result in a proliferation delay of 1.2 h/Gy (1.2 h/100 rad) or 1.4 h/Gy (1.4 h/100 rad), respectively, in 64 h cultures: The duration of delays had a linear relationship with doses from 2 to 8 Gy (200 to 800 rad).