300 keV FEG Electron Cryo Microscope for Single Particle Analyses and Tomography

用于单粒子分析和断层扫描的 300 keV FEG 冷冻电子显微镜

• 批准号: 329548431
• 金额: --
• 依托单位: Ludwig-Maximilians-Universität München (LMU)
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/329548431?language=en
• 关键词: 300; keV; FEG; Electron; Cryo

The recent technological developments in cryo-electron microscopy (cryo-EM) have led to a dramatic breakthrough with respect to improved resolution and, therefore, in its applicability. Using the novel direct electron detectors the two main applications of cryo-EM, single particle analysis and cryo-tomography, now routinely reach resolutions around 3 Å and 10 Å, respectively. This makes single particle cryo-EM the method of choice for a broad range of questions in structural biology that have usually been addressed by X-ray crystallography. In the case of cryo-tomography the improved resolution allows for the identification of individual macromolecular complexes in their native cellular environment and, after sub-tomogram averaging, the recognition of nucleic acid and protein secondary structure. As a result, this development has led to an explosion in the demand for data collection time, in particular, since increasingly smaller particles and also native, non-abundant complexes can be successfully subjected to structure determination. However, the currently available equipment at the Gene Center cannot satisfy this demand: firstly, the capacity of one high-end microscope is insufficient as to meet the increasing needs. Secondly, the existing equipment is optimized for fully automated high-through-put data collection of large particles. Consequently, data with optimal quality cannot be collected for smaller particles or for cryo-tomography. Therefore, we apply to purchase a second high-end cryo-microscope, which, in general, is expected to increase available data collection options and time. More specifically, the proposed microscope is planned to be equipped with a phase plate, an energy filter and a direct detector, thus allowing analysis of small particles as well as cryo-tomography applications.

低温电子显微镜(CRYO-EM)的最新技术发展导致了在提高分辨率方面的重大突破，因此在其适用性方面也取得了重大突破。使用新型的直接电子探测器，低温电子显微镜的两个主要应用--单粒子分析和低温层析成像--现在通常分别达到约3？和10？的分辨率。这使得单粒子冷冻-EM成为解决结构生物学中通常由X射线结晶学解决的广泛问题的首选方法。在冷冻断层扫描的情况下，改进的分辨率允许在其自然细胞环境中识别单个大分子复合体，并且在亚断层图像平均之后，识别核酸和蛋白质的二级结构。结果，这一发展导致了对数据收集时间的需求的爆炸性增长，特别是因为越来越小的颗粒以及天然的、非丰富的络合物可以成功地进行结构确定。然而，目前基因中心现有的设备不能满足这一需求：首先，一台高端显微镜的能力不足以满足日益增长的需求。其次，对现有设备进行了优化，以实现大颗粒的全自动高通量数据采集。因此，不能为更小的颗粒或低温层析成像收集质量最佳的数据。因此，我们申请购买第二台高端冷冻显微镜，预计这将增加可用的数据收集选项和时间。更具体地说，拟议的显微镜计划配备一个相位板、一个能量过滤器和一个直接探测器，从而能够分析小颗粒以及低温层析成像应用。