Acquistion of a High-Pressure Freezing/Freeze Substition System for Electron Tomography and Immunocytochemistry

该奖项部分支持芝加哥大学电子显微镜（EM）核心设施的高压冷冻和冷冻替代仪器的收购。 这项技术将允许生物学家利用免疫细胞化学和电子断层扫描的最新发展进行先进的EM。与标准醛固定相比，冷冻固定具有在毫秒内固定细胞结构的优点，从而避免常见的固定伪影，例如形状变化和膜融合。 冷冻固定对于免疫细胞化学是有用的，因为结构可以很好地保存而不丧失抗原性。 在高压下进行冷冻固定允许相对厚的样品被冷冻而不被冰晶形式损坏。 这种方法特别适用于电子断层扫描，这使得生物结构能够以纳米分辨率进行三维重建。 近年来，电子断层扫描技术已成为研究细胞器重塑、膜运输和有丝分裂纺锤体动力学等细胞过程的有力工具。 芝加哥大学的几位研究人员与其他机构的研究小组合作，对酵母、原生生物和哺乳动物细胞进行高压冷冻和/或电子断层扫描，这里的其他细胞生物学和生理学研究人员需要这些技术来回答紧迫的科学问题。 新技术的用户将包括博士后，研究生和大学实验室的本科生，以及访问大学进行暑期研究实习的本科生。 高压冷冻在芝加哥或附近地区还没有，因此所要求的系统也将是附近机构研究人员的一个有价值的补充。 此外，新的设备和方法将被纳入研究生和本科生的课堂教学。

This award partially supports the acquisition of a high-pressure freezing and freeze substitution instruments for the electron microscopy (EM) Core facility at the University of Chicago. This technology will allow biologists to perform advanced EM by taking advantage of recent developments in immunocytochemistry and electron tomography. Compared to standard aldehyde fixation, cryofixation has the advantage of immobilizing cellular structures within milliseconds, thereby avoiding common fixation artifacts such as shape changes and membrane fusion. Cryofixation is useful for immunocytochemistry because structure can be well preserved without loss of antigenicity. Performing cryofixation at high pressures allows relatively thick samples to be frozen without being damaged by ice crystal formaton. This method is particularly appropriate for electron tomography, which enables biological structures to be reconstructed in three dimensions at nanometer resolution. In recent years, electron tomography has become a powerful tool for studying cellular processes such as organelle remodeling, membrane trafficking, and mitotic spindle dynamics. Several researchers at the University of Chicago have collaborated with groups at other institutions to perform high-pressure freezing and/or electron tomography of yeast, protist, and mammalian cells, and other cell biology and physiology researchers here need these techniques to answer pressing scientific questions. Users of the new techniques will include postdocs, graduate students, and undergraduates in University labs, as well as undergraduates who visit the University for summer research internships. High-pressure freezing has not been available in Chicago or the immediate vicinity, so the requested system will also be a valuable addition for researchers at nearby institutions. In addition, the new equipment and methods will be incorporated into classroom teaching at the graduate and undergraduate levels.