Atomic resolution cryo-EM at 200 keV

Atomic resolution in cryo-electron microscopy was first demonstrated six years ago. This was accomplished using 300 kV electron microscopes equipped with new hardware that provided narrower energy spread, aberration correction and energy filtering. Here, we report the achievement of 1.24 Å atomic resolution on an upgraded 200 kV electron microscope featuring a cold field emission gun, a high-resolution objective lens polepiece and an energy filter. These components transform the instrument into a cost-effective single-particle cryo-EM platform with performance comparable to that of significantly more expensive 300 kV systems. The microscope can also be operated at 100 kV and by using a high-speed hybrid-pixel detector we were able to reach sub-2 Å resolution.