HIGH PRESSURE CRYOCOOLING FOR BIOLOGICAL X-RAY DIFFRACTION MICROSCOPY

用于生物 X 射线衍射显微镜的高压低温冷却

• 批准号: 8363562
• 负责人: ENJU LIMA
• 金额: $ 0.52万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363562
• 关键词: Algorithms; Biological; Cellular Structures; Collaborations; Freezing; Funding; Goals; Grant; Ice; Image; Microscopy; Molecular; National Center for Research Resources; Noise; Phase; Principal Investigator; Problem Solving; Reporting; Research; Research Infrastructure; Resolution; Resources; Sampling; Solutions; Source; Staging; Testing; United States National Institutes of Health; X ray diffraction analysis; X-Ray Diffraction; cost; cryogenics; improved; pressure; prevent

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We have developed cryogenic x-ray diffraction microscopy (cryo-XDM) for imaging hydrated, unstained biological samples and recently reported the first frozen-hydrated images of D. radiodurans with 8 keV x-rays at a resolution of 30 to 50 nm. Having shown the feasability of cryo-XDM in biological imaging, we hope to improve the resolution toward 10 nm to visualize fine cellular structures, possibly at the molecular level. So far, one of the main challenges in reaching this goal has been the ice condition. During the plunge-freezing stage, samples can become contaminated with crystalline ice which can result in increased noise levels preventing the phasing algorithm from finding a solution. To solve this problem we plan to utilize high-pressure freezing samples to preserve them in the amorphous ice state in collaboration with Dr. S. Gruner and Dr. C.U. Kim at Cornell. We request 1 day beamtime to test the feasibility of applying high-pressure freezing for biological XDM.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 我们已经开发了低温X射线衍射显微镜（cryo-XDM），用于成像水合的、未染色的生物样品，最近报道了第一个D.在30至50 nm的分辨率下，使用8 keV X射线的耐辐射铀。在展示了cryo-XDM在生物成像中的可行性之后，我们希望将分辨率提高到10 nm，以可视化精细的细胞结构，可能在分子水平上。到目前为止，实现这一目标的主要挑战之一是冰况。在急冻阶段，样品可能被结晶冰污染，这可能导致噪声水平增加，从而阻止定相算法找到解决方案。为了解决这个问题，我们计划与S。格鲁纳和C. U.康奈尔大学的金我们要求1天的射束时间来测试将高压冷冻应用于生物XDM的可行性。