使用倾斜校正扫描透射电子显微镜对厚样品进行剂量有效的冷冻电子显微镜检查，这一成果由康奈尔大学Lena F. Kourkoutis课题组经过不懈努力而取得。相关论文于2025年9月23日发表在《自然—方法学》杂志上。

而不是以降低电位信号为代价过滤掉非弹性散射，正如在能量过滤透射电子显微镜中所做的那样，研究组展示了如何快速获得剂量效率和未过滤的图像，主题倾斜校正的亮场扫描透射电子显微镜数据收集在像素化检测器上。对于厚度超过500nm的完整细菌细胞和大型细胞器，与能量过滤透射电子显微镜相比，倾斜校正的亮场扫描透射电子显微镜的二维图像对比度增强，剂量效率提高3 - 5倍。为了证明该技术在结构确定方面的性能，该团队提出了一个亚纳米分辨率的单粒子分析图，用于从789个粒子中确定高度对称的病毒样粒子。

据悉，低温电子显微镜是结构生物学的有力工具。在厚样品中，挑战出现了，因为透射电子的一个指数大的部分失去能量，从非弹性散射和不能再正确聚焦，由于色差在样品后光学的结果。

附：英文原文

Title: Dose-efficient cryo-electron microscopy for thick samples using tilt- corrected scanning transmission electron microscopy

Author: Yu, Yue, Spoth, Katherine A., Colletta, Michael, Nguyen, Kayla X., Zeltmann, Steven E., Zhang, Xiyue S., Paraan, Mohammadreza, Kopylov, Mykhailo, Dubbeldam, Charlie, Serwas, Daniel, Siems, Hannah, Muller, David A., Kourkoutis, Lena F.

Issue&Volume: 2025-09-23

Abstract: Cryogenic electron microscopy is a powerful tool in structural biology. In thick specimens, challenges arise as an exponentially larger fraction of the transmitted electrons lose energy from inelastic scattering and can no longer be properly focused as a result of chromatic aberrations in the post-specimen optics. Rather than filtering out the inelastic scattering at the price of reducing potential signal, as is done in energy-filtered transmission electron microscopy, we show how a dose-efficient and unfiltered image can be rapidly obtained using tilt-corrected bright-field scanning transmission electron microscopy data collected on a pixelated detector. Enhanced contrast and a 3–5× improvement in dose efficiency are observed for two-dimensional images of intact bacterial cells and large organelles using tilt-corrected bright-field scanning transmission electron microscopy compared to energy-filtered transmission electron microscopy for thicknesses beyond 500nm. As a proof of concept for the technique’s performance in structural determination, we present a single-particle analysis map at sub-nanometer resolution for a highly symmetric virus-like particle determined from 789 particles.

DOI: 10.1038/s41592-025-02834-9

Source: https://www.nature.com/articles/s41592-025-02834-9