The Relative Biological Efficiency of 20-Mev Electrons and 250-Kvp X-Rays in Saccharomyces cerevisiae Inactivation

Abstract
The results indicate that the RBE for 250-kvp X-rays and 20 Mev electrons for yeast cells is not constant. The over-all precision of the experiments was such that it is unlikely that the variations in RBE observed were due to experimental errors. These conclusions are reinforced by the fact that the RBE values obtained were very close either to 0.82 or to 1.00; intermediate values were not observed. The RBE is in some way related to the age of the population and its budding state as shown by its variation from culture to culture and with the age of the culture.