CTF determination and correction in electron cryotomography
CTF determination and correction in electron cryotomography
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DOI：
10.1016/j.ultramic.2006.02.004
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发表时间：
2006-05-01
期刊：
影响因子：
2.2
通讯作者：
Crowther, R. A.
中科院分区：
文献类型：
--
作者：
Fernandez, J. J.;Li, S.;Crowther, R. A.
电子冷冻断层扫描（cryoET）有潜力在分子分辨率上阐明复杂生物标本的结构，但技术和计算仍然需要改进。这项工作解决了在低温低温下电子显微镜的对比度传递函数（CTF）的测定和校正。我们的CTF检测和离焦确定方法依赖于基于条带的周期图平均，扩展到整个倾斜系列，以克服低温et中发现的低对比度条件。提出了一种处理倾斜试样图像离焦梯度的CTF校正方法。这些CTF测定和校正的方法已经应用于多形性标本和单颗粒的低温et的几个例子。CTF校正对于提高分辨率是至关重要的，特别是在那些结合低温et和单粒子平均技术的研究中。(c) 2006 Elsevier B.V.版权所有
Electron cryotomography (cryoET) has the potential to elucidate the structure of complex biological specimens at molecular resolution but technical and computational improvements are still needed. This work addresses the determination and correction of the contrast transfer function (CTF) of the electron microscope in cryoET. Our approach to CTF detection and defocus determination depends on strip-based periodogram averaging, extended throughout the tilt series to overcome the low contrast conditions found in cryoET. A method for CTF correction that deals with the defocus gradient in images of tilted specimens is also proposed. These approaches to CTF determination and correction have been applied here to several examples of cryoET of pleomorphic specimens and of single particles. CTF correction is essential for improving the resolution, particularly in those studies that combine cryoET with single particle averaging techniques. (c) 2006 Elsevier B.V. All rights reserved.