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

分析透射电子显微镜（TEM）和冷冻转移系统（补充场发射扫描电子显微镜（SEM）并扩大其能力）将被放置在乔治亚大学的高级超微结构研究中心。近50年来，透射电子显微镜（TEM）为我们对细胞结构和功能、晶体结构、分类学、微生物群落结构、材料分析和无数其他领域的理解做出了重大贡献。今天，透射电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）和结构细胞生物学领域。同样，扫描电镜在矿物和其他材料的表征中起着至关重要的作用。新的TEM将满足生物学家和非生物学家的研究需求，并将作为佐治亚大学的主要研究TEM。为了给最大数量和最多样化的研究人员提供最大的好处，TEM必须能够做的不仅仅是拍摄高倍率的图像。它必须能够进行电子衍射、x射线微分析和断层扫描的高倾斜成像，并适用于低温透射电镜等技术。同样，冷冻转移系统将补充该中心已有三年历史的场发射扫描电镜。LEO 982是市场上分辨率最高（20KeV时1.5 nm）的sem之一。配备了轻元素EDS x射线微分析系统，背向散射探测器和高分辨率透镜内二次电子探测器，该中心的扫描电镜能够满足许多佐治亚大学科学家的研究需求。冷冻转移系统将允许检查水化标本。在常规的标本制备过程中，样品必须使用有机溶剂和临界点干燥或冷冻干燥脱水。在这一过程中，高度水化的标本，如多糖基质、油和粘土浆料往往发生显著变化。同样，容易受到干扰或难以保存在其自然状态下的样品（例如，底物上的细菌或真菌菌丝）可以在此过程中被洗掉，因此从图像中获得的数据可以显着改变。冷冻转移系统允许快速冷冻样品并直接在扫描电镜中检查。虽然这种技术对许多常规标本来说是不合适的，甚至是不必要的，但它通常是某些标本可以检查的唯一方法。LEO 982的低温传输能力的增加将大大增加该仪器的实用性和多功能性，并允许格鲁吉亚研究人员目前无法尝试的许多新应用。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项目的发展中发挥着重要作用。近年来，该中心的作用已经扩大到包括共聚焦、定量荧光、数字成像和分析，该中心现在是大学的核心显微镜和成像设施。这些设备可供佐治亚大学和其他地区机构的研究人员使用，并纳入该中心的学生培训计划，其中包括显微镜、细胞生物学、地质学、食品科学的正式课程，以及非正式的参观。

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.