Fig. 3: Using HFBI film to solve the preferred orientation problem of catalase.

a–c Representative cryo-EM micrographs (scale bar, 20 nm) of catalase vitrified using the ANTA foil grid in thin ice (a), in thicker ice (b) and vitrified using the HFBI film covered ANTA foil grid (c). The corresponding representative 2D class averages of catalase are shown in the middle. The percentage of the number of particles in each class is labelled accordingly. The computed orientation distributions with the cryo-EF values are shown at the bottom. The number of particles used to calculate the cryo-EF values is indicated accordingly. d Cryo-EM map of catalase at a resolution of 2.29 Å that was solved using the HFBI film-covered ANTA foil grid. A representative region of the cryo-EM map is magnified (right) with the fitted atomic model. Scale bar, 2 Å. e 3D-FSC plot of cryo-EM reconstruction of catalase using the HFBI film covered ANTA foil grid.