Figure 1
Imaging lysozyme nanocrystal in imaging and diffraction mode. The top-left panel shows the Fourier transform of a 300 keV electron image of a ±100 nm-thick lysozyme nano-crystal (measured at Scherzer focus) collected using a Titan Krios EM with a Falcon direct electron detector (Nederlof et al., 2013). The illuminated crystal volume was about 400 nm × 200 nm × 100 nm and the electron dose was about 6 e− Å−2. The lower-left panel indicates the signal-to-noise ratio of this imaging data. The circle indicates 3 Å resolution. A peak search routine identified potential Bragg spots above background (van Genderen et al., 2016). The average peak height of these spots was plotted as a function of resolution with a solid line. The average diffuse background was plotted with a dotted line. The top right panel shows a diffraction pattern of a lysozyme nanocrystal. The crystal had a very similar size to the crystal of the left panel and had the same space group. The 200 keV data were collected using a Titan Krios EM equipped with a Medipix direct electron detector. The diffracted crystal volume was about 1000 nm × 200 nm × 100 nm and the electron dose was 0.06 e− Å−2. The lower-right panel indicates the plot which was calculated in a similar way to the corresponding lower-left plot of the imaging data. |