200 keV FEG Electron Cryo Microscope

大分子的最高分辨率结构生物学分析需要最佳的样品制备。除了完整的生化表征外，这种优化还特别包括冷冻制备（玻璃化）本身，这需要在初步EM分析反馈的指导下进行系统的迭代方法。在这种优化中，例如测试各种印迹条件以确保最佳保存、最终样品取向和冰条件。该筛选包括采集用于初步处理的数据集，以更好地表征样品的构象状态。一个200 keV FEG电子低温显微镜与直接电子探测器和机器人样品更换满足这些要求。考虑到Titan Krios在单粒子cryoEM方面已经可以预见的超额认购，这款显微镜将确保良好的工作流程，只有特征良好的样品和成熟的项目才能转移到高端仪器上。此外，该仪器将满足较薄标本的分子cryoET和从cryoFlB-SEM出来的标本的初始表征的需要。在高端仪器上使用通用自动网格样品格式的可能性允许在显微镜上高效地进行样品处理，并使用户能够获得处理高端仪器所有主要功能的经验。系统的样本筛选和转移成功率在自动装载机上明显高于“侧入式”系统。将EM放置在S3区域中，进一步允许分析传染性物质。与高端仪器一起，涵盖了非常广泛的样品。

Highest resolution structural biology analyses of macromolecules require optimal sample preparation. Besides a full biochemical characterisation this optimisation includes particularly the cryo preparation (vitrification) itself that requires a systematic iterative approach guided by feedback from preliminary EM analyses. In this optimisation e.g. various blotting conditions are tested to ensure best preservation, ultimate sample orientation and ice condition. This screening includes acquisition of data sets for preliminary processing, to allow better sample characterisation with respect to conformational states. A 200keV FEG electron cryo microscope with direct electron detector and robotic Sample changer fulfils these requirements. Given the already foreseeable oversubscription of the Titan Krios for single particle cryoEM, this microscope will ensure a good workflow and that only well-characterised samples and matured projects move on to the top-end instrument. Further, the instrument will serve the needs of molecular cryoET of thinner specimens and initial characterisation of the specimens coming off the cryoFlB-SEM. The possibility to use the common autogrid sample format with the high-end instruments allows efficient sample progression across the microscopes and enables users to gain experience with handling all the major functionality of the high-end instruments. Systematic sample screening and transfer success is significantly higher on autoloader than in ‘side-entry' systems. Putting the EM in a S3 area, further allows for analyses of infectious material. Together with the top-end instruments a very wide range of samples is covered.