Energy filter with fast-counting direct electron detector

带有快速计数直接电子探测器的能量过滤器

• 批准号: 525040890
• 金额: --
• 依托单位: Julius-Maximilians-Universität Würzburg
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2023
• 资助国家: 德国
• 起止时间: 2022-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/525040890?language=en
• 关键词: Energy; filter; fast; counting; direct

Researchers at the Julius-Maximilians-Universität Würzburg investigate the structural determinants by which biological assemblies support a diverse set of functionalities. In 2018 they established an electron cryo microscopy facility for high-resolution structure determination. This facility is used by researchers in and beyond Würzburg. At the heart of the platform is a 300 kV electron microscope with a Schottky type XFEG emitter and a direct electron detector. The detector enables data acquisition in linear mode and in counting mode. The latter gives a detective quantum efficiency, which is close to the theoretical limit. However, due to its low frame rate it limits the throughput to only about 700 movies per day. In contrast, linear mode allows data acquisition of up to 7,000 movies a day but with only about half of the detective quantum efficiency of the counting mode. Sparked by the success with data obtained at the facility, the ambitions of the researchers at the JMU have shifted towards more challenging projects such as smaller, and more dynamic complexes and ligand localization for drug discovery. The success of these projects depends on large data sets with some 5000 movies obtained in counting-mode. With the current equipment, acquisition of such data sets can take a week and more. Even worse, for smaller dynamic complexes (< 150 kDa), the scouting data obtained within 24 hours are often insufficient for judging whether a structure would likely be solved if a larger data set were obtained. Therefore, the current detection system with a slowly counting camera does not fulfill the needs and ambitions of the researchers at the JMU with respect to quality and quantity of image data obtained within a 24-hour slot. To establish whether a different detection system will be more suitable for the needs, researchers compared data obtained for the same sample in Würzburg and elsewhere. These comparisons showed that in addition to counting, energy filtration and zero-loss imaging are other important assets which enable more robust classification of small dynamic complexes and drastically improve the overall resolution. To bring the platform to the current leading standards in image acquisition, we apply for replacing the current detection system with an energy filter and a direct electron detector with fast counting capabilities.

维尔茨堡朱利叶斯·马克西米利安大学的研究人员研究了生物组装体支持多种功能的结构决定因素，他们于 2018 年建立了用于高分辨率结构测定的电子冷冻显微镜设施。该设施供维尔茨堡内外的研究人员使用。该平台的核心是一个 300 kV 电子显微镜，配有肖特基型 XFEG 发射器和直接电子探测器，可提供数据。线性模式和计数模式下的采集提供了接近理论极限的侦探量子效率，但由于其帧速率较低，因此将吞吐量限制为每天约 700 部电影。每天可以采集多达 7,000 部电影的数据，但侦探量子效率只有计数模式的一半左右。由于在该设施获得的数据取得了成功，JMU 研究人员的雄心已转向更具挑战性的项目。比如更小、更多这些项目的成功取决于以计数模式获得的约 5000 个电影的大型数据集，使用当前的设备可能需要一周甚至更长时间。对于较小的动态复合物（< 150 kDa），24小时内获得的探测数据通常不足以判断如果获得较大的数据集是否可能解决结构，因此，当前具有缓慢计数相机的检测系统无法满足要求。的需要和JMU 研究人员对 24 小时内获得的图像数据的质量和数量的期望 为了确定不同的检测系统是否更适合需求，研究人员比较了维尔茨堡和维尔茨堡的同一样本获得的数据。这些比较表明，除了计数之外，能量过滤和零损失成像也是重要的资产，可以对小型动态复合物进行更稳健的分类，并显着提高整体分辨率，使该平台达到当前图像采集的领先标准。 ，我们申请更换带有能量滤波器和具有快速计数功能的直接电子探测器的电流检测系统。