Download MendeleyCharacterizing the resolution and throughput of the Apollo direct electron detector.
Peng, R., Fu, X., Mendez, J.H., Randolph, P.S., Bammes, B.E., Stagg, S.M.(2023) J Struct Biol X 7: 100080-100080
- PubMed: 36578473
- DOI: https://doi.org/10.1016/j.yjsbx.2022.100080
- Primary Citation of Related Structures:
8EHG, 8EMQ, 8EN7 - PubMed Abstract:
Advances in electron detection have been essential to the success of high-resolution cryo-EM structure determination. A new generation of direct electron detector called the Apollo, has been developed by Direct Electron. The Apollo uses a novel event-based MAPS detector custom designed for ultra-fast electron counting. We have evaluated this new camera, finding that it delivers high detective quantum efficiency (DQE) and low coincidence loss, enabling high-quality electron counting data acquisition at up to nearly 80 input electrons per pixel per second. We further characterized the performance of Apollo for single particle cryo-EM on real biological samples. Using mouse apoferritin, Apollo yielded better than 1.9 Å resolution reconstructions at all three tested dose rates from a half-day data collection session each. With longer collection time and improved specimen preparation, mouse apoferritin was reconstructed to 1.66 Å resolution. Applied to a more challenging small protein aldolase, we obtained a 2.24 Å resolution reconstruction. The high quality of the map indicates that the Apollo has sufficiently high DQE to reconstruct smaller proteins and complexes with high-fidelity. Our results demonstrate that the Apollo camera performs well across a broad range of dose rates and is capable of capturing high quality data that produce high-resolution reconstructions for large and small single particle samples.
Organizational Affiliation:
Institute of Molecular Biophysics, 91 Chieftain Way, Florida State University, Tallahassee, FL 32306, United States.
