SYNCHROTRON X-RAY FLUORESCENCE MICRO-TOMOGRAPHY OF CELLS

该计划的目标是开发一种研究资源 研究微量元素在细胞过程中的作用， 将元素定位在细胞的细胞器内， 同步辐射诱导的微米级计算机断层扫描（CT） 荧光X射线。 因为荧光CT只需要 最低限度地准备，厚样品， 污染应该比那些 需要对标本进行物理切片。 荧光CT 应保持同步辐射的高灵敏度 感应X射线发射。 为了确定可行性，X射线微探针（1）的光束在 国家同步加速器光源将被准直到10 微米点。 样本将平移和旋转（2）通过 使用当前安装的CT设备（3）的射束。 铁 将从培养的小鼠中检测荧光X射线 肝细胞 将检测到透射的X射线 从而荧光和吸收 可以重建断层图像。 除了显示是否 铁的浓度可以在细胞器内映射，这项研究 将有助于阐明铁在自由基反应中的作用 导致氧依赖性组织损伤。 第二阶段a 1 - 2微米荧光CT专用装置 解决方案将被设计和建造。

The objective of this program is to develop a research resource for studying the role of trace elements in cellular processes by localizing the elements within the organelles of the cell using micron scale computed tomography (CT) of synchrotron induced fluorescent X-rays. Because fluorescence CT needs only minimally prepared, thick samples, the probability of contamination should be much lower than for techniques which require the physical sectioning of the specimen. Fluorescence CT should retain the high sensitivity of Synchrotron Radiation Induced X-ray Emission. To determine feasibility, the beam of the X-ray microprobe (1) at the National Synchrotron Light Source will be collimated to a 10 micron spot. Samples will be translated and rotated (2) through the beam using the presently installed CT apparatus (3). Iron fluorescence X-rays will be detected from cultured mouse hepatocytes. Transmitted X-radiation will be detected simultaneously so that both fluorescence and absorption tomograms can be reconstructed. In addition to showing whether concentrations of iron can be mapped within organelles, this study will help to clarify the role of iron in the free radical reactions that contribute to oxygen dependent tissue injury. In phase II, a specialized apparatus for fluorescence CT with 1 or 2 micron resolution will be designed and built.