Single floating cell irradiation technique with an X-ray microbeam

A single floating cell irradiation technique with X-ray microbeam has been developed for the microscopic research of radiation effects on floating cells in a liquid medium. This technique is a combination of X-ray microbeam and laser technologies. A preliminary experiment on the survival of budding cells of the yeast Saccharomyces cerevisiae (RAD52) was performed with the X-ray microbeam system. Micro-pits were fabricated on the bottom of a culture dish in a liquid medium, using green laser beams. The yeast cells were put into the micro-pits one by one by using focused infrared laser beams. A 50-kV X-ray microbeam 12 μm (FWHM) in diameter was propagated into the targeted yeast cell. The maximum dose rate on the targeted cell was estimated to be 0.09 Gy/s from the results of beam profile measurements and photon-electron transport calculations. The X-ray irradiation effect on the cell lethality was clearly observed for the cell exposed to X-rays of 100 Gy.