view article
Figure 2
Experimental setup of the serial synchrotron crystallography experiment. (a) Schematic macroscopic illustration of the serial helical line-scan approach using a standard cryogenic loop, imaged with the inline microscope. (b) SEM image of isolated in vivo grown cathepsin B microcrystals on a silicon support. Red arrows illustrate the serial helical line scan. The incident beam is represented by the red `flare'. The colour density in the flare is proportional to a calculated two-dimensional Gaussian function with FWHM 4 × 5 µm, with relative size to the 10 µm scale bar, showing a significant fraction of photon flux away from the centre of the beam. Red dots illustrate the positions of collected frames during the line scan with an oscillation width of 0.5° each. The graph (lower part) visualizes the delivered dose per area against arbitrary coordinates, indicating a total dose per area fluctuating between 50 and 60% owing to the ratio of FWHM of the beam and the gap between each line-scan position. (c) After the serial helical line scan, the photoinduced ionization at the exposed part of the sample is macroscopically visible. (d) Heatmap of diffraction images in the crystal loop after pre-selection using CrystFEL. The colour bar codes the average intensity of Bragg peaks in each diffraction pattern as an indication of the diffraction strength in each pattern.

IUCrJ
Volume 1| Part 2| February 2014| Pages 87-94
ISSN: 2052-2525
doi:10.1107/S2052252513033939