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

摘要 需要资金购买直接电子探测器和先进的操作软件 泰坦·克里奥斯透射式电子显微镜。新一代直接电子探测器 取代闪烁体和ccd来记录EM图像，并提供高度戏剧性的 在灵敏度和分辨率方面都有改进。所要求的猎鹰II摄像头还将提供 数据采集率比我们现有的CCD摄像机提高了三倍，但主要是 优势来自于信噪比的大幅提高和极大的改善 点扩展函数。而图像获取速度的三倍增长是可以满足的 使用我们现有的CCD摄像机，只需在三倍长的时间内采集图像，而不是 用CCD获取的大量图像将永远无法恢复高分辨率信息 这要么完全没有出现在ccd图像中，要么被淹没在噪声中。这些进展包括 直接电子探测器将使我们能够以一种 史无前例的解决方案，极大地帮助了许多NIH支持的项目。四大用户 (埃格尔曼、耶格尔、斯图尔特和张)和一些次要用户将使用泰坦·克里奥斯作为 一个共享的设施。这台显微镜与建议的摄像机(~)的吞吐量令人难以置信。 每天2,000张图像)，结合全天候机器人操作的显微镜 时间表，意味着数据分析将成为限速步骤，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发挥设施的作用，为 结构生物界。将在高分辨率上检查的标本 带有建议检测器的Krios范围从病毒和细菌毛到涉及 对外来RNA的先天免疫识别，允许在概念上的进展 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.