Application of microbeam in bio-science and life science. V. Biological effect of low dose radiation studied by using a synchrotron X-ray microbeam irradiation system

Use of synchrotron X-ray microbeam has enabled studies to irradiate the organism at cellular level and this paper describes the necessity of the microbeam equipment, findings obtained, equipment that authors have developed, and their own results. The equipment is to irradiate cell(s) and to distinguish the targeted cells on the defined coordinate from non-irradiated ones. There are microbeams of accelerated particles and photons with various energies. Synchrotron-generated low-energy X-ray microbeam has an advantage of efficiently giving imparted energy to the limited area like a single cell, based on whose concept authors have developed such an apparatus in their facility and been presenting for use by general researchers. One of outstanding results brought about by microbeam is the examination of the bystander effect and of desirable ones in future is the dose assessment in biological effects at the lower dose range than that studied hitherto. The X-ray microbeam is thus an important tool for studying the effect of low dose radiation. (T.I.)