Cryo-Preparation Unit for Scanning Electron Microscope

扫描电子显微镜冷冻制备装置

• 批准号: RTI-2017-00028
• 负责人: Goff, HDouglas
• 金额: $ 10.93万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616527
• 关键词: Cryo; Preparation; Unit; Scanning; Electron

This application requests a new low-temperature (cryo-) sample preparation system for the newly-acquired (2016) high-resolution Field Emission-Scanning Electron Microscope (FE-SEM), which is located in the University of Guelph’s Advanced Analysis Centre (AAC) core facility and managed by the Office of Research. The requested cryo-preparation unit is an immediate requirement to replace the outdated and not fully-functional cryo-preparation system (2004) currently installed on the antiquated low-resolution SEM (1986) in the Department of Food Science. In an effort to maximize potential users and streamline operations to maximize efficiency, the University has moved to centralize its electron microscopy equipment in a facility that will meet the needs of all microscopists across campus, other universities and industry. The acquisition of a new cryo-preparation system will allow the Department of Food Science to decommission their old SEM and to take advantage of the greatly-improved capabilities of the new FE-SEM. Sample preparation for conventional SEM requires chemical fixation and dehydration to prepare electron-stable samples for the high vacuum environment within the electron microscope chamber. Much of the current research that uses the Food Science facility requires cryo-preparation because biological samples and food materials are high in water, which is extremely volatile when viewed under high vacuum within conventional SEM, and therefore needs to be frozen in a cryo-preparation system to view the fully hydrated structure. For biological and food samples, such as fruits, vegetables and plant tissues, dairy and meat emulsions, lipid systems, and bacteria and bacterial and fungal biofilms, a cryo- system can prepare samples in a ‘close to real’ condition. These applications suffer greatly from artifacts caused by conventional chemical fixation and drying steps. The ability to freeze the sample and immobilize the water allows for imaging after minimal sample preparation and therefore also minimal distortion. The present system has had tremendous use during its 12-year life but is now beyond its useful life as parts and service are no longer available. A new system will have improved temperature control and better vacuum for faster and more precise sample preparation. By locating the sample cryo-preparation system on the Quanta 250 FE-SEM in the AAC there will now be huge research gains to be made through the ability to image frozen samples at nanometer resolution. The research programs to be supported with this equipment include those of the applicants, 4 from Food Science and 4 from Molecular and Cellular Biology, also 4 of which hold Canada Research Chairs and one an NSERC Industrial Research Chair, as well as numerous potential users once the facility is operational.

该应用要求为新收购的（2016年）高分辨率场发射扫描电子显微镜（FE-SEM）提供新的低温（冷冻）样品制备系统，该系统位于圭尔夫大学的高级分析中心（AAC）核心设施，并由研究办公室管理。所要求的冷冻制备装置是一个迫切需要，以取代过时的，不完全功能的冷冻制备系统（2004年），目前安装在过时的低分辨率扫描电镜（1986年）在食品科学系。为了最大限度地利用潜在用户并简化操作以最大限度地提高效率，该大学已将其电子显微镜设备集中在一个设施中，该设施将满足校园，其他大学和行业的所有显微镜工作者的需求。新的冷冻制备系统的收购将使食品科学系能够退役旧的SEM，并利用新的FE-SEM大大提高的能力。常规SEM的样品制备需要化学固定和脱水，以制备电子稳定的样品，用于电子显微镜室中的高真空环境。目前使用食品科学设施的大部分研究都需要冷冻制备，因为生物样品和食品材料的含水量很高，在传统SEM的高真空下观察时极易挥发，因此需要在冷冻制备系统中冷冻以观察完全水合的结构。对于生物和食品样品，如水果、蔬菜和植物组织、乳制品和肉类乳液、脂质系统以及细菌和细菌和真菌生物膜，低温系统可以在“接近真实的”条件下制备样品。这些应用极大地受到由常规化学固定和干燥步骤引起的伪影的影响。冷冻样品和水的能力允许在最小的样品制备后成像，因此也允许最小的失真。目前的系统在其12年的使用寿命中有很大的用途，但由于不再提供零件和服务，现在已经超过了其使用寿命。一个新的系统将具有更好的温度控制和更好的真空度，以实现更快、更精确的样品制备。通过将样品冷冻制备系统置于AAC中的Quanta 250 FE-SEM上，现在将通过以纳米分辨率对冷冻样品进行成像的能力取得巨大的研究成果。该设备支持的研究计划包括申请人的研究计划，其中4人来自食品科学，4人来自分子和细胞生物学，其中4人拥有加拿大研究主席，1人拥有NSERC工业研究主席，以及设施投入使用后的众多潜在用户。