Acquisition of an Analytical Transmission Electron Microscope and Cryo Scanning Electron Microscope

将在佐治亚大学高级超微结构研究中心放置一台分析型透射电子显微镜和一套冷冻传输系统(以补充场发射扫描电子显微镜并扩大其能力)。近50年来，透射电子显微镜在我们对细胞结构和功能、晶体结构、系统学、微生物群落结构、材料分析等无数领域的研究中做出了重要贡献。今天，透射电子显微镜在生物学研究中发挥着至关重要的作用，特别是在生物分子定位(如免疫金标记法)和结构细胞生物学领域。同样，扫描电子显微镜在矿物和其他材料的表征中起着至关重要的作用。新的瞬变电子显微镜将为生物学家和非生物学家的研究需要配备设备，并将作为佐治亚大学的主要研究瞬变电子显微镜。为了给最大数量和最多样化的研究人员提供最大的好处，瞬变显微镜必须能够做更多的事情，而不是拍摄高倍率图像。它必须能够进行电子衍射、X射线显微分析和用于断层成像的高倾斜成像，并适用于像CryoTEM这样的技术。同样，冷冻传输系统将补充该中心成立三年的场发射扫描电子显微镜。Leo 982是市场上分辨率最高的(20keV时为1.5 nm)扫描电子显微镜之一。该中心的扫描电子显微镜配备了轻元素EDS X射线显微分析系统、背向散射探测器和高分辨率透镜内二次电子探测器，能够满足佐治亚大学许多科学家的研究需求。冷冻转移系统将允许检查水合的样品。在常规的样品制备过程中，样品必须使用有机溶剂和临界点干燥或冷冻干燥进行脱水。在这个过程中，高度水合的标本，如多糖基质、油和泥浆，通常会发生显著的变化。同样，容易受到干扰或很难在自然状态下保存的样本(例如，底物上的细菌或真菌菌丝)可以在这个过程中被洗掉，因此从图像中获得的数据可能会被显着改变。冷冻转移系统允许人们快速冷冻样品，并在扫描电子显微镜中直接进行检查。虽然这项技术对许多常规标本来说并不合适，甚至是不必要的，但它往往是检查某些标本的唯一方法。LEO 982的冷冻传输能力的增加将显著提高该仪器的实用性和多功能性，并允许许多佐治亚州研究人员目前无法尝试的新应用。该中心在20个不同部门和150多个独立实验室的研究生培训和研究计划的发展中发挥着重要作用。近年来，该中心的作用已扩大到包括共焦、定量荧光、数字成像和分析，该中心现在是该大学的核心显微镜和成像设施。来自佐治亚大学和其他地区机构的研究人员可以使用这种设备，并将其纳入该中心的学生培训计划，该计划包括显微镜、细胞生物学、地质学、食品科学的正式课程，以及非正式参观。

An analytical transmission electron microscope (TEM) and a cryotransfer system (to complement a field emission scanning electron microscope (SEM) and expand its capabilities) will be placed in the Center for Advanced Ultrastructural Research at the University of Georgia. For nearly 50 years transmission electron microscopy (TEM) has been making significant contributions to our understanding of cell structure and function, crystal structure, systematics, microbial community structure, materials analysis, and countless other fields. Today TEM plays a crucial role in biological research especially in the areas of biomolecular localization (e.g. immunogold labeling) and structural cell biology. Likewise SEM plays an essential role in the characterization of minerals and other materials. The new TEM will be equipped for the research needs of biologists and non-biologists and will serve as the primary research TEM for the University of Georgia. In order to provide the greatest benefit to the largest and most diverse number of researchers a TEM must be able to do more than take high magnification images. It must be capable of performing electron diffraction, X-ray microanalysis, and high tilt imaging for tomography and be adaptable for techniques such as cryoTEM. Similarly the cryotransfer system will complement the Center's three-year-old field emission SEM. The LEO 982 is one of the highest resolution (1.5 nm at 20KeV) SEMs on the market. Equipped with a light element EDS X-ray microanalysis system, backscatter detector, and in-lens secondary electron detector for high resolution, the Center's SEM is able to meet the research needs of many University of Georgia scientists. The cryotransfer system will allow for the examination of hydrated specimens. During conventional specimen preparation, samples must be dehydrated using organic solvents and critical point drying or freeze-drying. Highly hydrated specimens such as polysaccharide matrices, oils, and clay slurries are often significantly altered during this process. Likewise samples that are easily disturbed or are hard to preserve in their natural state (e.g. bacteria or fungal hyphae on a substrate) can be washed off during the process and thus the data acquired from the images can be significantly altered. A cryotransfer system allows one to rapidly freeze a sample and examine it directly in the SEM. While this technique is not appropriate or even necessary for many routine specimens it is often the only method by which certain specimens can be examined. The addition of cryotransfer capabilities to the LEO 982 will significantly increase the utility and versatility of this instrument and allow for many new applications that cannot presently be attempted by Georgia researchers. The Center plays an essential role in the development of graduate training and research programs for 20 different departments and more than 150 individual laboratories. In recent years, the Center's role has expanded to include confocal, quantitative fluorescence, and digital imaging and analysis, and the Center now functions as a core microscopy and imaging facility for the University. This equipment is available to researchers from the University of Georgia as well as other regional institutions and incorporated into the student-training program of the Center, which includes formal courses in microscopy, cell biology, geology, food sciences, as well as informal tours.