A Versatile High Resolution Low Vacuum FEG SEM for the Biosciences and Interdisciplinary Research

场发射枪扫描电子显微镜（FEG-SEM）是一种能够产生样品表面非常高分辨率图像的显微镜。它在生物和材料科学中有广泛的应用，研究人员希望在广泛的放大范围内可视化和分析样品的表面。场发射枪扫描电子显微镜可用于在大的表面区域成像，可用于成像块状材料以及薄膜或斑点，现代显微镜可以成像小至一或两纳米的结构。传统的FEG-SEM要求样品在高真空下成像，这意味着样品，例如湿的生物材料，会产生大量干扰图像的蒸汽。为了通过传统的FEG-SEM可视化生物标本，标本必须干燥和涂覆，这可能会扭曲结构图像。另一种形式的扫描电镜，称为环境扫描电镜（ESEM），允许样品在低压气体环境和高湿环境中可视化，这意味着生物样品可以在水合状态下直接或在冷冻状态下成像。在这个应用程序中，我们正在寻求取代传统的扫描电镜，这是27年的历史，仍然需要胶片处理（不能获取数字图像），并经常发生故障。我们希望购买一个多功能的高分辨率低真空FEG-SEM和一个冷冻工作站。在生物科学领域，特别是组织工程、生物材料、结构分子和细胞生物学的研究中，大量当前和未来的项目都需要显微镜。显微镜要求，是最通用的高分辨率场发射枪电子显微镜可扩展的低真空能力。一个主要的特点是，它使用一个工具，而过去需要多个系统。扫描电镜有高真空、低真空和环境扫描（ESEM）三种工作模式。在不同模式下可实现的分辨率为1纳米。该设备将直接取代生物科学学院目前电子显微镜单元中的旧扫描电镜。不需要翻新。设备的使用将由学院资助的全职技术人员提供支持。该显微镜将被用于对众多研究人员和研究生进行的一系列不同标本进行成像。将被成像的标本包括用于组织工程的三维胶原支架、附着在组织工程支架上并在其中生长的细胞、用于髋关节和膝关节置换的生物材料产生的纳米颗粒、身体组织和环境样本中的纳米颗粒、病毒颗粒、引起疾病的蛋白质原纤维，如淀粉样蛋白和朊病毒蛋白，以及导致肌肉收缩和细菌移动的蛋白质。

Field emission gun scanning electron microscopy (FEG-SEM) is a type of microscopy capable of producing very high resolution images of the surface of a sample. It has a wide range of applications in biological and materials science in which researchers wish to visualise and analyse the surface of a sample over a wide range of magnifications. Field emmision gun scanning electron microscopy can be used to image over a large surface area, can be used to image bulk materials as well as thin films or spots and modern microscopes can image structures as small as one or two nanometres. Conventional FEG-SEM requires samples to be imaged under a high vacuum which means that specimens, for example biological materials which are wet, would produce a lot of vapour which interferes with the images. To visualise biological specimens by conventional FEG-SEM the specimens have to be dried and coated, which can distort images of structures. Another form of SEM, called environmental SEM (ESEM) allows samples to be visualised in low pressure gaseous environments and high humidity which means that biological samples can be imaged in their hydrated state either directly or in the frozen state. In this application we are seeking to replace a conventional SEM which is 27 years old, still requires film processing (does not acquire digital images) and frequently breaks down. We wish to purchase a versatile high resolution low-vacuum FEG-SEM and a cryo-workstation. The microscope is critically required for a large number of current and future projects in biological sciences, in particular research in tissue engineering, biomaterials, structural molecular and cellular biology. The microscope requested, is the most versatile high resolution feild emmision gun electron microscope available with extended low-vacuum capabilities. A major feature is that it does with a single tool, what used to require multiple systems. The scanning electron microscope has three modes of operation: high vacuum, low vacuum and environmental scanning (ESEM). The resolution achievable under different modes is 1-nanometres. The equipment will directly replace the old SEM in the current electron microscope unit in the Faculty of Biological Sciences. No refurbishment will be required. The use of the equipment will be supported by a Faculty funded full time technician. The microscope will be used to image a range of different specimens carried out by numerous researchers and postgraduate students. Examples of specimens that will be imaged include three dimensional collagenous scaffolds which are used in tissue engineering, cells adhering to and growing in tissue engineering scaffolds, nanoparticles produced by biomaterials used in hip and knee replacements, nanoparticles in body tissues and in environmental samples, virus particles, fibrils of proteins that cause disease such as amyloid and prion proteins and proteins that cause muscles to contract and bacteria to move.