Supplement for System for generation of frozen-hydrated samples using the Focused

描述(申请人提供)：透射式电子显微镜断层扫描提供纳米级的三维图像。它是生物电子显微镜中的一项主流技术，并在半导体和纳米技术行业迅速找到应用。在生物学方面，科学家们对制作准确的冷冻水合样本断层图像很感兴趣，因为以这种方式制备的样本被认为代表了体内的天然结构。在典型的哺乳动物细胞和组织的情况下，这种标本通常是高压冷冻的，然后准备使用冷冻-超显微切割法进行电子断层扫描。然而，冷冻超微切割的困难，以及机械切片不可避免地产生的伪影，阻碍了大多数实验室尝试用电子断层扫描来研究冷冻水合细胞和组织。我们的Wadsworth合作者的初步工作表明，使用冷冻-FIB系统避免了冷冻-超微切割术的伪影和困难，并在制备冷冻水合标本方面提供了额外的优势。与公共健康相关：这项提案将开发工具，使生物学家能够更清楚地了解细胞的结构和功能。这些知识是无数医学研究和实践领域的基础。

DESCRIPTION (provided by applicant): Transmission electron microscope (TEM) tomography provides three-dimensional images at the nanometer scale. It is a mainstream technique in biological electron microscopy, and is rapidly finding applications in the semiconductor and nanotechnology industries. In biology, scientists are interested in producing faithful tomograms of frozen-hydrated samples, since specimens prepared in this way are considered to represent the native in vivo structure. In the case of typical mammalian cells and tissue, such specimens are usually high- pressure frozen, and then prepared for electron tomography using cryo-ultramicrotomy. However the difficulties of cryo-ultramicrotomy, and the artifacts that are unavoidably created by mechanical sectioning, have discouraged most laboratories from attempting study of frozen-hydrated cells and tissue by electron tomography. Preliminary work by our Wadsworth collaborators has shown that use of a cryo-FIB system avoids the artifacts and difficulties of cryo-ultramicrotomy, and offers additional advantages in preparing frozen-hydrated specimens. PUBLIC HEALTH RELEVANCE: This proposal will develop tools that allow biologists to get a clearer picture of the structure and function of the cell. This knowledge is fundamental to innumerable areas of medical research and practice.