Influence of total electron dose on the quality of nucleic acids potential maps in Cryo-EM

The standardization of protocols in science lies at the basis of every experiment. During this process, some crucial questions need to be answered. The quality of results in single particle cryo-Electron Microscopy (cryo-EM) requires optimized data collection parameters. Hence, before each experiment, the following questions need to be defined: (i) which optimal electron dose should be used? (ii) at which level does the accumulated electron damage start to affect resolution? (iii) how does pre-exposure influence the level of damage? (iv) how does dose weighting over the scale of total electron dose deposited to the sample influence the resulting reconstruction? In this manuscript, we addressed all of the above questions by performing a systematic analysis of the relation between data collection strategies and the resulting outcome in the form of cryo-EM map quality of Escherichia coli and H. sapiens ribosome particles. Our findings will serve as references for users seeking to optimize data collection and reconstruction routines for single particle cryo-EM experiments.