美国加州大学伯克利分校Holger Müller小组研制出用于透射电子显微镜的激光相位板。相关论文发表于10月刊的《自然—方法学》。

据介绍，用于快速冷冻的生物标本或冷冻电镜的透射电子显微镜（TEM）将受益于用于聚焦相差成像相位板的开发。目前已经研究了几种类型的相位板，但是所有这些设备的快速静电充电阻碍了发展。

研究人员使用高强度连续波激光束进行电子相位控制，并将其用作TEM的相位板。研究人员通过成像非晶碳膜来演示了该激光相位板。激光相位板提供了稳定且可调的相移，而没有静电电荷或有害的电子散射。这些结果表明对未染色生物大分子和细胞进行剂量有效成像的可能性。

附：英文原文

Title: Laser phase plate for transmission electron microscopy

Author: Osip Schwartz, Jeremy J. Axelrod, Sara L. Campbell, Carter Turnbaugh, Robert M. Glaeser & Holger Müller 

Issue&Volume: Volume 16 Issue 10

Abstract:

Transmission electron microscopy (TEM) of rapidly frozen biological specimens, or cryo-EM, would benefit from the development of a phase plate for in-focus phase contrast imaging. Several types of phase plates have been investigated, but rapid electrostatic charging of all such devices has hindered these efforts. Here, we demonstrate electron phase manipulation with a high-intensity continuous-wave laser beam, and use it as a phase plate for TEM. We demonstrate the laser phase plate by imaging an amorphous carbon film. The laser phase plate provides a stable and tunable phase shift without electrostatic charging or unwanted electron scattering. These results suggest the possibility for dose-efficient imaging of unstained biological macromolecules and cells.

DOI: 10.1038/s41592-019-0552-2

Source: https://www.nature.com/articles/s41592-019-0552-2