3-DIMENSIONAL RECONSTRUCTION OF SINGLE PARTICLES EMBEDDED IN ICE
3-DIMENSIONAL RECONSTRUCTION OF SINGLE PARTICLES EMBEDDED IN ICE
复制标题
DOI：
10.1016/0304-3991(92)90233-a
复制
发表时间：
1992-01-01
期刊：
影响因子：
2.2
通讯作者：
FRANK, J
中科院分区：
文献类型：
--
作者：
PENCZEK, P;RADERMACHER, M;FRANK, J
嵌入在冰中的单个粒子给图像处理带来了新的挑战，因为这种粒子在电子显微镜下具有固有的低信噪比。我们已经开发了解决其中一些问题的新技术，并将这些技术应用于大肠杆菌核糖体的电子显微照片。数据采集和重建遵循Radermacher等人的随机圆锥技术。[J.显微镜146(1987)113]。为了克服基于参考的算法在噪声非常大的情况下增强参考基序的倾向，开发了一种无参考比对算法。此外，还开发了一种基于卡方最小化约束的迭代三维重建方法，并对其进行了测试。该算法倾向于减少缺失角范围对重建的影响，从而便于从不同取向的粒子获得的随机-圆锥数据集的合并。
Single particles embedded in ice pose new challenges for image processing because of the intrinsically low signal-to-noise ratio of such particles in electron micrographs. We have developed new techniques that address some of these problems and have applied these techniques to electron micrographs of the Escherichia coli ribosome. Data collection and reconstruction follow the protocol of the random-conical technique of Radermacher et al. [J. Microscopy 146 (1987) 113]. A reference-free alignment algorithm has been developed to overcome the propensity of reference-based algorithms to reinforce the reference motif in very noisy situations. In addition, an iterative 3D reconstruction method based on a chi-square minimization constraint has been developed and tested. This algorithm tends to reduce the effects of the missing angular range on the reconstruction, thereby facilitating the merging of random-conical data sets obtained from differently oriented particles.