200 keV FEG Electron Cryo Microscope

对大分子进行最高分辨率的结构生物学分析需要最佳的样品制备。除了全面的生化特征外，这一优化还包括低温制备(玻璃化)本身，这需要由初步EM分析的反馈指导的系统迭代方法。在这种优化中，测试了各种吸印条件，以确保最好的保存、最终的样品定向和结冰条件。这种筛选包括获取用于初步处理的数据集，以允许关于构象状态的更好的样品表征。带有直接电子探测器和机器人换样器的200keV FEG电子低温显微镜满足了这些要求。考虑到Titan Krios对单粒子CryoEM的超额认购已经可以预见，这台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。此外，该仪器将满足较薄样品的分子冷冻和从低温扫描电子显微镜获得的样品的初步表征的需要。在高端仪器中使用通用AutoGrid样本格式的可能性允许在显微镜上高效地进行样本处理，并使用户能够获得处理高端仪器的所有主要功能的经验。自动进样器的系统样本筛选和转移成功率显著高于侧向进样系统。将EM放在S3区域，进一步允许对传染病材料进行分析。与最高端的仪器一起，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.