The yield of radiation-induced chromosomal aberrations in lymphocytes as related to the time of arrival at first post-stimulation mitosis.

Blood from 3 donors of each species, man, rabbit and pig, were irradiated with a dose of 2.5 Gy 60Co gamma-rays. Micro-cultures of lymphocytes, established in presence of BrdUrd, were harvested at 6 different times after stimulation by PHA. The preparations containing metaphase figures were stained according to Perry and Wolff to permit differentiation of the cells in first and later mitoses. In all individuals and species studied there was a highly significant negative correlation between dicentric yield and time from stimulation to harvest. The decline of the yield with time of harvest varied in 3 species between 1.0 and 3.6% per hour. Implications for biological dosimetry are discussed.