Learning goals

This chapter will help you to understand why input data curation is critical for cryoEM/ET, what happens when ‘bad’ data are not removed, and the appropriate parameters to ensure proper data ‘cleaning.’

Expected outcomes

At the end of this chapter, you will:

• Understand why bad micrographs and bad particles must be removed ahead of 3D analysis
• How tomographic reconstructions are affected by improper fiducial alignment

Recommended online materials

Contrast transfer function (CTF)

Guiding questions: What is defocus & why do we need to correct for it?

• Grant Jensen – Defocus & its affects
• Grant Jensen – CTF correction
• CryoEM Principles – Fourier transform: convolution, sampling and Nyquist

Single-particle analysis

• Grant Jensen – Basics
• Grant Jensen – Reconstruction overview

Sample preparation considerations

• CryoEM101 – Grid screening & evaluation