Direct Electron Detector for a Titan Krios Robotic Electron Cryo-Microscope

总结 请拨经费购买一台直接电子探测器和先进的操作软件， 泰坦克里奥透射电子显微镜新一代直接电子探测器 取代用于记录EM图像的放大器和CCD，并提供高度戏剧性的 提高了灵敏度和分辨率。Falcon II相机还将提供 三倍的数据收集率比我们现有的CCD相机，但主要的 优势来自于信噪比的大幅提高和 点扩散函数虽然获取图像的速度增加了三倍， 与我们现有的CCD相机，通过简单地获取图像超过三倍更长的时间，没有 用CCD获取的大量图像将恢复高分辨率信息 这在CCD图像中完全不存在，或者隐藏在噪声中。这些进步与 直接电子探测器将使我们能够以 前所未有的分辨率，极大地帮助了一些NIH支持的项目。四大用户 （Egelman，Yeager，Stewart和Zhang）和一些未成年人用户将使用Titan Krios作为 共用设施这台显微镜与拟议的相机令人难以置信的吞吐量（~ 每天2，000张图像），结合全天候的显微镜机器人操作 时间表，意味着数据分析将成为速率限制步骤，而不是图像采集。 这种高分辨率、高通量的成像模式将在很大程度上改变EM。因此，我们的克里奥斯 可以真正像同步加速器一样作为一种设施，为人类提供独特的服务。 结构生物学社区将在高分辨率上检查的标本 具有所提出的检测器的Krios范围从病毒和细菌皮利到涉及 先天免疫识别外源RNA，允许概念上的进步， 了解许多对人类健康很重要的系统。

Summary Funds are requested to purchase a direct electron detector and advanced operating software for a Titan Krios transmission electron microscope. The new generation of direct electron detectors replace scintillators and CCDs for recording EM images, and offer a highly dramatic improvement in both sensitivity and resolution. The Falcon II camera requested will also offer a three-fold increase in the data collection rate over our existing CCD camera, but the main advantage comes from the huge increase in the signal-to-noise ratio and the greatly improved point spread function. While the three-fold increase in the rate of acquiring images could be met with our existing CCD camera by simply acquiring images over a three-fold longer period, no amount of images acquired with the CCD would ever recover the high resolution information that is either completely absent in the CCD images or buried in the noise. These advances with the direct electron detector will allow us to image a large number of specimens at an unprecedented resolution, greatly aiding a number of NIH-supported projects. Four Major Users (Egelman, Yeager, Stewart and Zhang) and a number of Minor Users will use the Titan Krios as a shared facility. The incredible throughput of this microscope with the proposed camera (~ 2,000 images per day), combined with the robotic operation of the microscope on a 24/7 schedule, means that data analysis will become the rate-limiting step and not image acquisition. This high resolution, high throughput mode of imaging will largely transform EM. Thus, our Krios can truly function as a facility much like synchrotrons do in providing a unique service to the structural biology community. The specimens that will be examined at high resolution on the Krios with the proposed detector range from viruses and bacterial pili to complexes involved in the innate immune recognition of foreign RNA, allowing for conceptual advances in understanding many systems that are important to human health.