Radiation damage repair by subpopulations of stationary-phase CHO cells separated by centrifugal elutriation

The sensitivity of cells to radiation is strongly dependent on the position of the cells within the cell cycle. Since tissues and organs of living animals have characteristic cell division rates which can be perturbed by environmental changes, cell cycle dependence of cellular damage is an essential component of models which are generated in an attempt to correlate the effects in animals with cellular data. Cell cycle variations also provide additional data which may help elucidate the mechanisms controlling cellular damage. Since we have observed two repair rates in plateau phase CHO cells and since these cultures include cells held in various parts of the cycle, it is natural to suspect that the changes in sensitivity may be caused by different parts of the cell cycle. Experiments were performed utilizing centrifugal elutriation methods in order to obtain populations enriched with cells of specific ages