Accurate magnification determination for cryoEM using gold.

Autor: Dickerson JL; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK., Leahy E; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK., Peet MJ; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK., Naydenova K; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK., Russo CJ; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK. Electronic address: crusso@mrc-lmb.cam.ac.uk.
Jazyk: angličtina
Zdroj: Ultramicroscopy [Ultramicroscopy] 2024 Feb; Vol. 256, pp. 113883. Date of Electronic Publication: 2023 Nov 15.
DOI: 10.1016/j.ultramic.2023.113883
Abstrakt: Determining the correct magnified pixel size of single-particle cryoEM micrographs is necessary to maximize resolution and enable accurate model building. Here we describe a simple and rapid procedure for determining the absolute magnification in an electron cryomicroscope to a precision of <0.5%. We show how to use the atomic lattice spacings of crystals of thin and readily available test specimens, such as gold, as an absolute reference to determine magnification for both room temperature and cryogenic imaging. We compare this method to other commonly used methods, and show that it provides comparable accuracy in spite of its simplicity. This magnification calibration method provides a definitive reference quantity for data analysis and processing, simplifies the combination of multiple datasets from different microscopes and detectors, and improves the accuracy with which the contrast transfer function of the microscope can be determined. We also provide an open source program, magCalEM, which can be used to accurately estimate the magnified pixel size of a cryoEM dataset ex post facto.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 MRC Laboratory of Molecular Biology. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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