Reducing the effects of radiation damage in cryo-EM using liquid helium temperatures

• DOI: 10.1073/pnas.2421538122
• Publication Date: 2025-04-22T17:36:04Z
• Authors: Joshua L. Dickerson; Katerina Naydenova; Mathew J. Peet; Hugh Wilson; Biplob Nandy; Greg McMullan; Robert Morrison; Christopher J. Russo
• Keywords: Liquid nitrogen; Cryo-Electron Microscopy; radiation damage; Micrograph

The physical limit in determining the atomic structure of biological molecules is radiation damage. In electron cryomicroscopy, there have been numerous attempts to reduce effects damage by cooling specimen beyond liquid-nitrogen temperatures, yet all failed realize potential improvement for single-particle determination. We identified causes information loss at liquid-helium and overcome them using a combination nanoscale beam illumination gold support with 100 nm diameter holes. This allowed determination where every frame exposure contained more than was available cryomicroscopy matching expectations from crystal diffraction. Since hole smaller field view typical micrograph, edges foil are directly visible each micrograph. Protein that degraded tend aggregate holes can constitute significant fraction need minimal water-foil irradiation will both be important consider as new cryomicroscopes supports developed imaging extremely low temperatures reduced.