High-resolution cryo-EM using beam-image shift at 200 keV

Abstract

Recent advances in single-particle cryo-electron microscopy (cryo-EM) data collection utilizes beam-image shift to improve throughput. Despite implementation on 300 keV cryo-EM instruments, it remains unknown how well beam-image shift data collection affects data quality on 200 keV instruments and how much aberrations can be computationally corrected. To test this, we collected and analyzed a cryo-EM dataset of aldolase at 200 keV using beam-image shift. This analysis shows that beam tilt on the instrument initially limited the resolution of aldolase to 4.9[A]. After iterative rounds of aberration correction and particle polishing in RELION, we were able to obtain a 2.8[A] structure. This analysis demonstrates that software correction of microscope aberrations can provide a significant improvement in resolution at 200 keV.