Cryo-Preparation Unit for Scanning Electron Microscope

这项申请要求为新获得的(2016)高分辨率场发射扫描电子显微镜(FE-SEM)提供新的低温(低温)样品制备系统，该系统位于圭尔夫大学高级分析中心(AAC)的核心设施中，由研究办公室管理。所要求的低温制备装置是立即需要的，以更换目前安装在食品科学部陈旧的低分辨率扫描电子显微镜(1986)上的过时且功能不全的低温制备系统(2004年)。为了最大限度地扩大潜在用户并简化操作以最大限度地提高效率，该大学已采取行动，将其电子显微镜设备集中在一个设施中，以满足校园、其他大学和行业中所有显微镜工作者的需求。购买新的冷冻制备系统将使食品科学部能够使其旧的扫描电子显微镜退役，并利用新的FE-扫描电子显微镜大大改进的能力。常规扫描电子显微镜的样品制备需要化学固定和脱水，以便在电子显微镜腔内的高真空环境中制备电子稳定的样品。目前使用食品科学设施的许多研究都需要冷冻制备，因为生物样品和食品材料的水含量很高，在常规扫描电子显微镜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查看完全水合的结构。对于生物和食品样品，如水果、蔬菜和植物组织、乳制品和肉类乳剂、脂肪系统以及细菌和细菌和真菌生物膜，冷冻系统可以在接近真实的条件下制备样品。这些应用很大程度上受到传统化学固定和干燥步骤造成的伪影的影响。冻结样品和固定水的能力允许在最小的样品制备之后进行成像，因此也最大限度地减少了失真。目前的系统在其12年的使用寿命内有了巨大的用途，但现在已经超过了其使用寿命，因为不再提供部件和服务。一个新的系统将有更好的温度控制和更好的真空度，以便更快、更精确地制备样品。通过在AAC的广达250 FE-SEM上安装样品冷冻制备系统，现在将通过以纳米分辨率对冷冻样品进行成像的能力来获得巨大的研究成果。将由该设备支持的研究项目包括申请者的研究项目，其中4个来自食品科学，4个来自分子和细胞生物学，其中4个担任加拿大研究教席，1个担任NSERC工业研究教席，以及一旦设施投入使用，以及许多潜在用户。

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 The requested cryo-preparation unit is an immediate requirement to replace the outdated and not fully-functional cryo-preparation system (2004) currently installed on the antiquated low-resolution SEM (1986) in the Department of Food Science.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.