Cryo-Electron Microscopy of Enveloped Viruses Using an Upgraded Transmission Electron Microscope: Influenza Type A and B Viruses and SARS-CoV-2

• DOI: 10.3103/s0096392523700153
• Publication Date: 2024-03-11T13:03:14Z
• Authors: L. V. Kordyukova; A. V. Moiseenko; T. A. Timofeeva; I. T. Fedyakina

Cryo-electron microscopy (cryo-EM) is indispensable for the structural studies of enveloped viruses – dangerous pathogens of humans and animals. Yet, it requires highly specialized equipment as well as careful sample preparation. In this work, the capabilities of transmission electron microscope JEOL JEM-2100 equipped with cryo-transfer holder are used, and preliminary cryo-EM data for influenza A and B virus strains and SARS-CoV-2 inactivated with beta-propiolactone are presented. Image analysis allows: (1) to distinguish “empty” viral particles from “full” ones (containing nucleocapsid); (2) to visualize the lipid bilayer of the viral envelope; (3) identify influenza virus surface antigens and the M1 protein layer combined with the inner lipid monolayer; (4) distinguish different morphology of S-spikes on the surface of inactivated SARS-CoV-2 virions. The developed approach provides good image quality for both fundamental and applied research.