High-resolution single-particle imaging at 100–200 keV with the Gatan Alpine direct electron detector

• DOI: 10.1016/j.jsb.2024.108108
• Publication Date: 2024-06-28T00:20:01Z
• Authors: Lieza M. Chan; Brandon J. Courteau; Allison Maker; Mengyu Wu; Benjamin Basanta; Hev Mehmood; David Bulkley; David Joyce; Brian C. Lee; Stephen Mick; Cory Czarnik; Sahil Gulati; Gabriel C. Lander; Kliment A. Verba
• Keywords: Single-Particle Analysis

Developments in direct electron detector technology have played a pivotal role enabling high-resolution structural studies by cryo-EM at 200 and 300 keV. Yet, theory recent experiments indicate advantages to imaging 100 keV, energies for which the current detectors not been optimized. In this study, we evaluated Gatan Alpine detector, designed operation Compared K3, demonstrated significant DQE improvement these energies, specifically ∼ 4-fold Nyquist single-particle experiments, datasets yielded better than 2 Å resolution reconstructions of apoferritin 120 keV on ThermoFisher Scientific (TFS) Glacios microscope fitted with non-standard SP-Twin lens. We also achieved 3.2 reconstruction 115 kDa asymmetric protein complex, proving Alpine's effectiveness complex biological samples. In-depth analysis revealed that are comparable K3 remarkably, from TFS surpassed all but data Titan Krios GIF/K3. Additionally, show capability acquisition screening lower-end systems obtaining 3 aldolase detailed 2D averages 55 sample using side-entry cryo holder. Overall, performs well standard may potentially capture benefits lower accelerating voltages, bringing smaller sized particles within scope cryo-EM.