title: Radiation-induced gamma-H2AX in mammalian cells irradiated with a synchrotron X-ray microbeam.
abstract: In order to study the radiobiological effects from low dose radiation, a cell irradiation system using synchrotron X-ray microbeam has been developed, by which cells can be recognised individually and irradiated one by one with the desired dose of monochromatic X rays. The minimum beam sizes obtained are 2 microm with the focusing optics and 5 microm square with the non-focused beam, and the beam size can be changed easily with a high-precision slit in the case of a non-focused beam. Human fibroblast cells were individually irradiated with this system, and immunostained by gamma-H2AX antibody to visualise the DNA damage. Most of the fluorescent foci were observed in a localised area in cell nuclei, the size of which was almost the same as the beam size.
authors.affiliation: Photon Factory, High Energy Accelerator Research Organization KEK, Tsukuba 305-0801, Japan. noriko.usami@kek.jp
authors.forename: N
authors.initials: N
authors.lastname: Usami
authors.forename: M
authors.initials: M
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Eguchi-Kasai
authors.forename: H
authors.initials: H
authors.lastname: Maezawa
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D002478:Cells, Cultured; D004247:DNA / Q000235:genetics* / Q000528:radiation effects*; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005347:Fibroblasts / Q000502:physiology* / Q000528:radiation effects*; D006657:Histones / Q000235:genetics*; D006801:Humans; D008904:Miniaturization; D011829:Radiation Dosage; D017356:Synchrotrons / Q000295:instrumentation*; D014965:X-Rays
chemical_list: C468783:H2AX protein, human; D006657:Histones; D004247:DNA