Probing the Functional Activity Limits of Biomolecules Under Electron Irradiation

Liquid cell transmission electron microscopy (LC-TEM) has the potential to allow for high resolution imaging of biological dynamics in a fully hydrated environment. While electrons can allow for subnanometer spatial resolution, one drawback of their use is the unavoidable ionizing radiation damage resulting from inelastic scattering events. In aqueous environments, highly reactive radical species are generated during the damage process which can react with other nearby molecules thereby causing secondary chemical damage in the sample (1). The impact of these radicals on the chemistry of the sample has been a primary point of study for the LC-TEM field, although the effect of radiation driven chemistry changes on the physiology of biological systems is not fully clear. Morphological changes in bacteria irradiated with electrons in a liquid cell has been described (2, 3), but the thresholds for impacting biomolecule activity and functionality are not yet known.