Single particle imaging at x-ray free electron lasers (XFELs) has the potential to determine the structure and dynamics of single biomolecules at room temperature. Two major hurdles have prevented this potential from being reached, namely, the collection of sufficient high-quality diffraction patterns and robust computational purification to overcome structural heterogeneity. We report the breaking of both of these barriers using gold nanoparticle test samples, recording around 10 million diffraction patterns at the European XFEL and structurally and orientationally sorting the patterns to obtain better than 3-nm-resolution 3D reconstructions for each of four samples. With these new developments, integrating advancements in x-ray sources, fast-framing detectors, efficient sample delivery, and data analysis algorithms, we illuminate the path towards sub-nanometer biomolecular imaging. The methods developed here can also be extended to characterize ensembles that are inherently diverse to obtain their full structural landscape.

中文翻译：

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使用X射线激光对纳米粒子集合进行3D衍射成像

X射线自由电子激光器（XFEL）上的单颗粒成像具有确定室温下单个生物分子的结构和动力学的潜力。两个主要障碍阻止了这种潜力的实现，即，收集足够高质量的衍射图样和强大的计算纯化能力，以克服结构异质性。我们报告了使用金纳米颗粒测试样品突破了这两个障碍，在欧洲XFEL上记录了约1000万个衍射图样，并对这些图样进行了结构和方向分类，以获得四个样品中每一个都优于3 nm分辨率的3D重建图像。通过这些新的发展，整合了X射线源，快速成帧检测器，有效的样品输送和数据分析算法方面的先进技术，我们阐明了通往亚纳米生物分子成像的途径。这里开发的方法也可以扩展为表征固有不同的合奏以获得完整的结构景观。