Soft X-ray radiation effects on yeast cells with energies on and off the O(K) absorption edge by a soft X-ray microprobe.

The cell killing abilities of soft X-rays on and off the oxygen K-shell edges on yeast cells have been investigated using a micrometer soft X-ray microprobe from synchrotron radiation. The dose depositions at different X-ray energies in the cell were discussed. At the same time, the cells were irradiated by (60)Co gamma-rays and the abilities in inducing yeast cell killing were compared with those produced by soft X-rays. The results showed that soft X-rays on and off the O(K) edge had higher ability of radiation damage than (60)Co gamma-rays. The total killing abilities of the three soft X-rays on yeast cells were almost similar and the differences of the X-rays in inducing yeast cell killing on and off the O(K) edge were not obvious.