Fig. 4: Revitrification of sealed cryo samples eliminates preferred orientation.
From: Ultrathin liquid cells for microsecond time-resolved cryo-EM
a Reconstruction of the 50S ribosomal subunit from a conventional cryo sample (2.5 Å), with the angular distribution of the particles showing strong preferred orientation. b, c Reconstructions from sealed samples revitrified for 30 µs and 300 µs (one and ten 30 µs laser pulses, respectively) show similar resolutions of 2.4 Å and 2.7 Å. The sampling compensation factor (SCF*) improves from 0.53 to 0.99, indicating a near-isotropic angular distribution of the particles in sealed, revitrified samples. The volumes are shown with a threshold of 4.5 σ above the mean. To better illustrate the flexible regions, a transparent overlay is added, which displays the volumes after Gaussian filtering to 2.5 Å and with a threshold of 3 σ.
