From Tube to Structure: SPA Cryo-EM Workflow Using Apoferritin as an Example

Methods Mol Biol. 2021:2305:229-256. doi: 10.1007/978-1-0716-1406-8_12.

Abstract

In this chapter, we present an overview of a standard protocol to achieve structure determination at high resolution by Single Particle Analysis cryogenic Electron Microscopy using apoferritin as a standard sample. The purified apoferritin is applied to a glow-discharged support and then flash frozen in liquid ethane. The prepared grids are loaded into the electron microscope and checked for particle spreading and ice thickness. The microscope alignments are performed and the data collection session is setup for an overnight data collection. The collected movies containing two-dimensional images of the apoferritin sample are then processed to obtain a high-resolution three-dimensional reconstruction.

Keywords: Cryo-EM; Cryogenic Electron Microscopy; Sample Preparation; Single Particle Analysis; Standard Protocol; Workflow.

MeSH terms

  • Animals
  • Apoferritins / chemistry*
  • Apoferritins / ultrastructure
  • Cryoelectron Microscopy / instrumentation*
  • Cryoelectron Microscopy / methods*
  • Equidae
  • Freezing
  • Imaging, Three-Dimensional
  • Specimen Handling / methods*
  • Workflow

Substances

  • Apoferritins