An improved strategy for automated electron microscopic tomography
An improved strategy for automated electron microscopic tomography
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DOI：
10.1016/j.jsb.2004.02.005
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发表时间：
2004-08-01
影响因子：
3
通讯作者：
Agard, DA
中科院分区：
文献类型：
--
作者：
Zheng, QXS;Braunfeld, MB;Agard, DA
提出并实现了一种基于预测的自动电子显微层析成像方法。通过假设样品遵循简单的几何旋转并且光学系统可以根据光学轴和机械轴之间的偏移来表征，发现由于载物台倾斜而导致的在x、y和z方向上的图像移动可以以期望的精度（x-y位置为15 nm，焦点为100 nm）动态地预测。因此，显微镜光学系统（光束/图像移位和聚焦）可以被自动调整以在以每个倾斜角度拍摄投影图像之前补偿预测的图像移动。因此，在数据收集过程中，不需要记录额外的图像用于跟踪和聚焦，也不需要花费宝贵的设置时间来对载物台运动进行冗长的预校准。此外，该方案还发现，容忍一个显着程度的非偏心，并在收集定期和低温低剂量图像薄或厚的样品，即使在放大倍数大于62000倍和角步长为10度大是相当强大的。对于感兴趣的用户，该软件可以免费下载用于非营利用途在http://www.msg.ucsf.edu/tomography。(C)2004年爱思唯尔公司All rights reserved.
A prediction-based scheme is proposed and implemented for automated electron microscopic tomography. By assuming that the sample follows a simple geometric rotation and that the optical system can be characterized in terms of an offset between the optical and mechanical axes, it is found that the image movement in the x, y, and z directions due to stage tilt can be dynamically predicted with desired accuracy (15 nm in x-y position and 100 nm in focus). Thus, the microscope optical system (beam/image shift and focus) can be automatically adjusted to compensate for the predicted image movement prior to taking the projected image at each tilt angle. As a consequence, it is not necessary to either record additional images for tracking and focusing during the course of data collections or to spend valuable setup time in a lengthy pre-calibration of stage motions. Furthermore, this scheme is also found to tolerate a significant degree of non-eccentricity and to be quite robust in the collection of regular and cryo low-dose images on thin or thick samples even at magnifications greater than 62000x and angular step as large as 10degrees. For interested users the software can be freely downloaded for non-profit use at http://www.msg.ucsf.edu/tomography. (C) 2004 Elsevier Inc. All rights reserved.