SUPERTHIN SERIAL SECTIONING

我们正在开发一种技术， 塑料嵌入的生物材料比以往任何时候都要薄， 以前剪的。 我们购买了一台改良的超切割切片机 关于Leica，Inc.与Diatome U合作。发展 实验性的金刚石刀来研究实际的局限性 到切片厚度。 这些工具与隔离 房间，以尽量减少气流，振动阻尼表和适当的 样品块表面的方向和修剪，使我们能够 获得厚度小于11nm的连续切片。 这些 切片以合理的均匀度（_10%）切割，并可在 大数字（>100）。 通过用甲醇铀酰染色切片 乙酸酯和使用小物镜孔径在传统的TEM 在40或60kV下操作，我们能够获得良好的图像对比度。 实验与钻石刀，已减少包括 角度（<40倍）导致了截面的显著改善 质量，相对于颤振和压缩。 切片机和 金刚石刀似乎不再是限制因素， 厚度，所以我们现在把注意力转向其他因素，如 如样品制备、嵌入硬度和试块面设计。 通过这项工作，我们希望了解如何薄一套连续切片 可以被切割。

We are developing techniques for cutting serial sections of plastic embedded biological material that are thinner than have been previously cut. We have purchased a modified Ultracut-UCT microtome from Leica, Inc. and are working with Diatome U. to develop experimental diamond knives to investigate the practical limitations to section thickness. These tools, in conjunction with an isolation room to minimize air currents, a vibration damping table and proper orientation and trimming of the sample block face, have allowed us to obtain serial sections that are less than 11nm in thickness. These sections cut with reasonable uniformity (_10%) and may be obtained in large numbers (>100). By staining sections with methanolic uranyl acetate and using a small objective aperture in a conventional TEM operating at 40 or 60kV, we are able to obtain good image contrast. Experimentation with diamond knives that have decreased included angles (<40x) has resulted in noticeable improvements in section quality, with respect to chatter and compression. The microtome and diamond knives no longer appear to be the limiting factors in section thickness, so we are now turning our attention to other factors, such as sample preparation, embedment hardness and block face design. Through this work we hope to learn how thin a set of serial sections can be cut.