Diffraction apparatus and procedure in tomography X-ray diffraction imaging for biological cells at cryogenic temperature using synchrotron X-ray radiation
Diffraction apparatus and procedure in tomography X-ray diffraction imaging for biological cells at cryogenic temperature using synchrotron X-ray radiation
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DOI：
10.1107/s1600577518012687
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发表时间：
2018-11-01
影响因子：
2.5
通讯作者：
Torizuka, Yasufumi
中科院分区：
文献类型：
--
作者：
Kobayashi, Amane;Takayama, Yuki;Torizuka, Yasufumi
X射线衍射成像是一种用于可视化生物细胞结构的技术。在使用同步辐射的X射线衍射成像实验中，为了减少生物细胞中的辐射损伤，低温条件是必要的。保持在低温下的冷冻水合生物样品也不会干燥和起泡，这在真空条件下的湿样品中发生。在先前的研究中，使用衍射装置KOTOBUKI-1 [Nakasako等人（2013），Rev. Sci.仪器。84，093705]被构造用于在低温下通过利用低温罐进行X射线衍射成像，低温罐是在低温物理学中开发的冷却装置。在这项研究中，一个新的低温罐，适用于层析成像实验，已被开发。该盆可以使生物细胞相对于入射X射线束的方向在+/-170度的角度范围内旋转。在此，详细和性能的锅和杂项设备的报告，沿着建立的实验程序，包括标本制备。该装置已被用于层析成像实验中的三维结构的Cyanidioschyzon merolae细胞与一个近似的大小为5 μ m的分辨率为136 nm的可视化。根据实验结果，讨论了未来实验的必要改进和在最大耐受剂量范围内实验条件下可达到的分辨率极限。
X-ray diffraction imaging is a technique for visualizing the structure of biological cells. In X-ray diffraction imaging experiments using synchrotron radiation, cryogenic conditions are necessary in order to reduce radiation damage in the biological cells. Frozen-hydrated biological specimens kept at cryogenic temperatures are also free from drying and bubbling, which occurs in wet specimens under vacuum conditions. In a previous study, the diffraction apparatus KOTOBUKI-1 [Nakasako et al. (2013), Rev. Sci. Instrum. 84, 093705] was constructed for X-ray diffraction imaging at cryogenic temperatures by utilizing a cryogenic pot, which is a cooling device developed in low-temperature physics. In this study a new cryogenic pot, suitable for tomography experiments, has been developed. The pot can rotate a biological cell over an angular range of +/- 170 degrees against the direction of the incident X-ray beam. Herein, the details and the performance of the pot and miscellaneous devices are reported, along with established experimental procedures including specimen preparation. The apparatus has been used in tomography experiments for visualizing the three-dimensional structure of a Cyanidioschyzon merolae cell with an approximate size of 5 mu m at a resolution of 136nm. Based on the experimental results, the necessary improvements for future experiments and the resolution limit achievable under experimental conditions within a maximum tolerable dose are discussed.