Single-particle cryo-EM data acquisition by using direct electron detection camera

Abstract

Recent advances in single-particle electron cryo-microscopy (cryo-EM) were largely facilitated by the application of direct electron detection cameras. These cameras feature not only a significant improvement in detective quantum efficiency but also a high frame rate that enables images to be acquired as 'movies' made of stacks of many frames. In this review, we discuss how the applications of direct electron detection cameras in cryo-EM have changed the way the data are acquired.

Keywords: direct electron detection camera; electron cryo-microscopy; single-particle cryo-EM.

Fig. 1.

Comparison of images recorded from different ice thicknesses. Images of frozen hydrated ribosome particles without a supporting carbon film were recorded from different areas of the same grid. FFT (a) of an image from thin ice (c) has visible Thon rings at ∼3 Å resolution. FFT (b) of an image from thick ice (d) has fewer Thon rings.

Fig. 2.

Influence of ice thickness on CTF. With the average defocus set to −1 μm, the CTF were averaged over different ice thickness: 500 Å (red), 1000 Å (green), 1500 (light blue) and 2000 Å (dark blue). The envelope of the CTF drops significantly with increasing ice thickness.