Acquisition of X-Ray Microanalysis System and Related Specimen Preparation Instrumentation for Electron Microscopy

摘要生物科学电子显微镜实验室是威斯康星大学密尔沃基分校生物科学系的教学和研究机构。目前，该设施中的电子显微镜供生物科学、物理、材料、机械和土木工程系以及五大湖研究中心和表面研究实验室的学生和工作人员使用。每一组的研究人员都表示需要结合目前正在进行的结构研究进行定量和定性的元素分析。威斯康星大学密尔沃基分校的生物科学电子显微镜(BSEM)实验室和表面研究实验室(LSS)正在要求建立一套仪器系统，以升级现有的电子显微镜，以满足这一需求。该仪器分为三组：分析、生物样品制备和材料样品制备。研究人员的分析需求将通过为现有的扫描电子显微镜和透射电子显微镜购买能量色散X射线光谱仪(EDS)来满足，这两个仪器都位于BSEM实验室。用于元素分析的生物样品的制备与传统的化学固定不兼容，但需要专门的技术和仪器。因此，我们需要用于处理扫描和透射电子显微镜的元素分析的生物样品的低温设备。最后，对于无机材料，需要专门的设备来制备平面图和横截面样品，以便在透射电子显微镜中对表面、界面和小颗粒进行成像、衍射和元素分析。所要求的设备将补充现有的扫描电子显微镜材料制备仪器。这一仪器系统将被用作威斯康星大学研究和研究生培训计划的组成部分。所要求的仪器将为生物科学研究以及材料和工程研究开辟新的可能性，使正在进行的项目和未来计划中的研究都受益。冷冻固定与元素测绘相结合，将使生物科学系和五大湖研究中心的研究人员更好地了解原核生物和真核生物在水环境中生物地球化学循环中的机制和影响。此外，冷冻制备仪器将极大地提高免疫定位研究的能力。材料样品加工所需的切割和细化设备是脆性和延性材料的透射电子显微镜分析所必需的。该仪器将用于制备用于元素分析和现有透射电子显微镜成像的薄截面和平面图样品；还将用于制备原子分辨率200KV场发射透射电子显微镜的样品，目前正在寻求单独的资金(国家科学基金/数字MR 9406752；材料研究仪器计划)。最后，切割和抛光工具将有助于在扫描电子显微镜中为大块样品的元素分析准备合适的平面。

ABSTRACT The Biological Sciences Electron Microscope Laboratory is a teaching and research facility in the Department of Biological Sciences at the University of Wisconsin-Milwaukee (UWM). Currently, the electron microscopes in this facility are being used by students and staff in Biological Sciences, Physics, and the Materials, Mechanical and Civil Engineering departments as well as the Center for Great Lakes Studies and the Laboratory for Surface Studies. Researchers in each of these groups have expressed a need for quantitative and qualitative elemental analysis in conjunction with the structural studies currently being conducted. The Biological Sciences Electron Microscopy (BSEM) Laboratory and the Laboratory for Surface Studies (LSS) at the University of Wisconsin- Milwaukee (UWM) are requesting a system of instruments to upgrade the existing electron microscopes in order to meet this need. This instrumentation falls into 3 equipment groupings: analytical, biological specimen preparation and materials specimen preparation. The analytical needs of the researchers will be met through the acquisition of energy dispersive x-ray spectrometers (EDS) for the existing scanning electron microscope (SEM) and transmissions electron microscope (TEM) both of which are located in the BSEM lab. The preparation of biological specimens for elemental analysis is not compatible with conventional chemical fixation, but requires specialized techniques and instrumentation. Therefore, we are requesting cryogenic equipment for processing biological samples for elemental analysis for both scanning and transmission electron microscopy. Finally, for inorganic materials, specialized equipment is needed for the preparation of plan-view and cross-sectional specimens to allow the imaging, diffraction and elemental analysis of surfaces, interfaces and small particles in TEM. The requested equipment will complement the existing instrumentation for SEM materials pr eparation. This system of instruments will be used as an integral part of the research and graduate training programs at UWM. The requested instrumentation will open up new possibilities for research in the biological sciences as well as in materials and engineering research benefiting both ongoing projects and future planned research. Cryofixation combined with elemental mapping will enable researchers in the department of Biological Sciences and the Center for Great Lakes Studies to gain a better understanding of the mechanisms and impact of prokaryotic and eukaryotic organisms in biogeochemical cycling in aquatic environments. In addition, the cryo-preparation instrumentation will greatly enhance the capacity for immunolocalization studies. The cutting and thinning equipment requested for materials specimen processing is required for TEM analysis of brittle and ductile materials. This instrumentation will be used for the preparation of thin cross-sectional and plane-view specimens for elemental analysis and imaging with the existing TEM; it will also be required for the preparation of specimens for an atomic resolution 200kV field emission TEM, for which separate funding is being sought (NSF/DMR 9406752; the Instrumentation for Materials Research Program). Finally, the cutting and polishing tools will aid in the preparation of suitable flat surfaces for elemental analysis of bulk specimens in the SEM.