| Project/Area Number |
16360476
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear engineering
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| Research Institution | Osaka University |
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Principal Investigator |
IIDA Toshiyuki Osaka University, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (60115988)
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| Co-Investigator(Kenkyū-buntansha) |
HORIIKE Hiroshi Osaka University, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (20252611)
SHIMIZU Kikuo Osaka University, Radioisotope Research Center, Associate Professor, ラジオアイソトープ総合センター, 助教授 (20162696)
SATO Fuminobu Osaka University, Graduate School of Engineering, Assistant, 大学院工学研究科, 助手 (40332746)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥15,400,000 (Direct Cost: ¥15,400,000)
Fiscal Year 2006: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2005: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2004: ¥10,200,000 (Direct Cost: ¥10,200,000)
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| Keywords | X-ray microbeam / optical tweezers / micro pit / DNA damage / normal human fibroblasts / fluorescence microscopy / radiophoto luminescent / 線量評価 / マイクロフォーカスX線源 / 蛍光X線元素分析 / 光学顕微鏡観測 / マイクロX線ビーム / バイスタンダー効果 |
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| Research Abstract |
A tabletop X-ray microbeam system with optical tweezers was developed for the microscopic research of radiation effects on cells in liquid culture. An X-ray beam from an X-ray tube with a 50 kV thin electron beam was converged by use of a glass capillary, which realized an X-ray beam spot of 12 μm (FWHM) in diameter. The maximum dose rate on a targeted cell in liquid culture was estimated to be 0.05 Gy/s from results of beam profile measurements and photon-electron transport calculations.
A preliminary experiment on the survival of budding cells of yeast, Saccharomyces cerevisiae (RAD52) was performed with the present X-ray microbeam system. Micro pits were made on an agar layer in a culture dish by use of a green laser, and then the budding yeast cells were put in the micro-pits one by one with the optical tweezers, i.e. a focused infrared laser. The X-ray irradiation effect on the cell lethality was clearly observed for the cells exposed to X-rays of 100 Gy.
RPL (RadioPhotoLuminescent)
… More
glass plates of 1 mm thickness were used to measure the X-ray microbeam profile. The image of the beam profile was obtained with a fluorescence microscope. In addition, images of DNA double strand breaks of the targeting cells on the RPL glass plate was obtained in the fluorescence antibody technique. Normal human fibroblasts (AG01522B) were grown in a RPL glass plate in Eagle's minimum essential medium. The sample plate was set in an X-ray microbeam system. A single cell was irradiated with the X-ray microbeam. The absorbed dose for the targeting cell was 5 Gy.
After the irradiation, the sample cells were stained with anti-γ H2AX antibody and fluorescence-labeled secondary anti-body, Alexa Fluor【○!R】 488 goat anti-mouse IgG F(ab')2 fragment conjugate. In addition, the nuclei of cells were stained with propidium iodide. The foci in the nucleus indicates the DNA damages produced by the X-ray beam. A RPL image of the X-ray beam was also obtained with the fluorescence microscope. In this way, the images of DNA damages and the X-ray beam profile at the same position could be successfully obtained with the fluorescent microscopy. Less
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