Advantages and operational strategies of Falcon 3EC for high resolution cryo-electron microscopy of biological macromolecules

The Falcon 2 camera (Thermo Fisher Scientific Inc., USA) mounted in High Resolution Bio-TEM at Korea Basic Science Institute (KBSI) was upgraded to Falcon 3EC in August 2017 (Jeong et al., 2017). Compared with Falcon 2, Falcon 3EC has better sensitivity and higher frame rate and can be operated in electron counting mode. These changes significantly increase the data quality, thereby increasing the resolution of the 3D structure. In the benchmarking test of this machine, the structure of inhibitor-free beta-galactosidase has been solved at 2.16 Å. Here we introduce main features of the new detector, and discuss about major considerations required for its operation and data collection strategies to achieve the near atomic resolution.