Analysis and comparison of electron radiation damage assessments in Cryo-EM by single particle analysis and micro-crystal electron diffraction

Exploiting the full potential of cryo-EM maps

The Coulomb potential maps generated by electron microscopy (EM) experiments contain not only information about the position but also about the charge state of the atom. This feature of EM maps allows the identification of specific ions and the protonation state of amino acid side chains in the sample. Here, we summarize qualitative observations of charges in EM maps, discuss the difficulties in interpreting the charge in Coulomb potential maps with respect to distinguishing it from radiation damage, and outline considerations to implement the correct charge in fitting algorithms.

Treatment of noise caused by radiation damage during cryo-EM data collection

Here, we discuss how noise that is caused by radiation damage during cryo-EM data collections accumulates during single-particle analysis (SPA), MicroED, and cryo-ET. For MicroED and SPA, bad data can be identified and excluded during data collection and processing, whereas cryo-ET will require systematic radiation damage assessments that can be derived from SPA.