MRI: Acquisition of a High-Resolution Electron Tomography System

配备倾斜样品保持器的中压（300 kV）电子显微镜用于断层扫描和冷冻台，为威斯康星州-麦迪逊大学的各种生物和生物工程研究项目提供关键成像技术。这种显微镜的用户在很大程度上依赖于高分辨率成像，他们的工作范围广泛的重要课题，包括膜和蛋白质运输，生物矿物和生物聚合物，病毒复制和病毒-宿主相互作用，细胞骨架组织和细胞分裂，神经末梢组织和胞吐作用，细菌结构，分子复合物的成像和神经工程。这种成像系统使研究人员能够在一系列倾斜角度上收集相对较厚样品的多个图像。所有这些图像都经过数学处理，以生成原始切片的3D重建（断层图像）。增加的加速电压对于允许电子束穿透样品而没有复数或非弹性散射是必不可少的，特别是在截面厚度加倍或接近三倍的高倾斜角下，生物样品或冷冻固定的生物标本或生物聚合物的塑料截面的电子断层照片导致2-10 nm的轴向分辨率。新设备安装在现有的高效校园显微镜和表征中心，由一名全职博士专家管理，完全由中心预算资助，并由一个专门的教师用户咨询委员会监督。新的断层扫描系统促进了校园内的许多合作，并允许来自几乎每一个学院/学校的研究人员和学生应用最先进的高分辨率成像技术。PI和co-PI教授的成像课程中包括关于拟议EM的使用和应用的动手演示。此外，每年举办夏季讲习班，以培训研究人员和学生在校园内的断层摄影方法。新的显微镜在推广方面也发挥了非常重要的作用。三维断层模型是视觉上令人惊叹的表示。它们以非常有效的方式将细胞结构的3D信息传达给每个人，从训练有素的生物学家到普通大众。新的威斯康星州发现研究所（WID）在市中心有一个显微镜和成像发现利基，其中包括一个高分辨率的显示器阵列组成的显示器。来自使用新的显微镜，包括复制病毒，细胞分裂过程中的细胞骨架阵列，植物细胞器，神经元中的信号传输的图像断层重建，显示在这些监视器。此外，一些断层扫描模型在3D打印机中打印，以在WID和其他参与部门中显示。

The intermediate voltage (300kV) electron microscope equipped with a tilting sample holder for tomography and a cryostage is serving a longstanding need to provide key imaging technologies to a wide variety of biological and bioengineering research programs on the University of Wisconsin - Madison. Users of this microscope are heavily dependent on high resolution imaging for their work on a wide range of important topics, including membrane and protein trafficking, biomineral and biopolymers, viral replication and virus-host interaction, cytoskeletal organization and cell division, nerve terminal organization and exocytosis, bacterial architecture, imaging of molecular complexes, and neuroengineering. This imaging system enables researchers to collect multiple images of relatively thick samples over a series of tilt angles. All these images are mathematically processed to generate a 3D reconstruction (tomogram) of the original section. The increased acceleration voltage is essential for allowing the electron beam to penetrate the sample without plural or inelastic scattering, especially at high tilt angles where the section thickness doubles or nearly triples Electron tomograms of either plastic sections of biological samples or cryofixed biological specimens or biopolymers results in an axial resolution of 2-10 nm. The new equipment is housed in an existing, highly effective campus microscopy and characterization center, managed by a permanent, full-time PhD expert entirely funded by the center budget, and supervised by a dedicated advisory committee of faculty users.The new tomographic system fosters many collaborations on campus and allows researchers and students from almost every single college/school to apply state-of-the-art high resolution imaging techniques. Hands-on demonstrations on the use and applications of the proposed EM are included in the imaging courses taught by the PI and co-PIs. In addition, annual summer workshops are held to train researchers and students on campus on tomographic approaches. The new microscope has also a very important role in outreach. Three-dimensional tomographic models are visually stunning representations. They convey 3D information of cellular structures in a very effective way to everyone, from highly trained biologists to the general public. The new Wisconsin Institute of Discovery (WID) has a microscope and imaging discovery niche in the Town Center that includes a high resolution display consisting of an array of monitors. Tomographic reconstructions derived from the use of the new microscope, including images of replicating viruses, cytoskeletal arrays during cell division, plant organelles, signal transmission in neurons, are displayed in these monitors. In addition, some tomographic models are printed in a 3D printer for display in the WID and other participating Departments.