Subtomogram averaging by cryo electron tomography using CRYO ARM™ 300 II for purified and cellular samples

Abstract

Cryo electron tomography (cryo-ET) enables three-dimensional visualization of biological macromolecules in their near-native environments, bridging the gap between structural and cellular biology. In this study, we evaluated high-resolution subtomogram averaging (STA) using a cryo-TEM (CRYO ARM^TM 300 II, JEOL) and PACEtomo software system for both single-particle analysis (SPA) type grids and lamellae prepared by cryo-focused ion beam (cryo-FIB) milling (JIB-4700F, JEOL). Using mouse apoferritin and E. coli ribosomes in thin vitreous ice film, resolutions of 2.04 Å and 2.86 Å were achieved, respectively. Using cryo-FIB lamellae of Salmonella cells, in situ ribosome structures were resolved to 8.2 Å resolution.

Keywords

cryo-EM / cryo-ET / STA / cryo-FIB-SEM / CryoLameller / CRYO ARM / structural cell biology

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