Figure 2: Snapshot diffraction patterns and LCP extrusion.
From: Lipidic cubic phase injector facilitates membrane protein serial femtosecond crystallography
(a,b) Single femtosecond snapshot diffraction patterns. (a) Diffraction spots from A2A adenosine receptor microcrystals in 9.9 MAG/cholesterol LCP to 2.5 Å and strong powder diffraction rings from crystalline lipid. (X-ray intensity attenuated to 7%, 1.5 μm X-ray beam diameter, 50-fs pulse length, 9.5 keV, 15 μm LCP jet diameter, 300 pl min−1 flow rate, 1 Hz pulse rate, crystal size: 1 × 1 × 5 μm3). (b) Diffraction from serotonin receptor 5-HT2B in cholesterol-doped 9.9 MAG+7.9 MAG LCP. No sharp rings are visible suggesting that formation of Lc phase has been avoided (X-ray intensity attenuated to 3.1% due to strong Bragg diffraction from 5 × 5 × 5 μm3 sized crystals, 1.5 μm X-ray beam diameter, 50-fs pulse length, 9.5 keV, 50 μm LCP jet diameter, 190 nl min−1 flow rate, 120 Hz pulse rate). The resolution at the detector edge in both panels is 2.5 Å. Panels (c) and (d): 9.9 MAG LCP extrusion in vacuum viewed between crossed polarizers. The tapered end of the capillary nozzle is seen protruding out of the gas aperture. Capillary inner diameter: 30 μm. (c) with He as co-flowing gas. Birefringence (bright flecks) is an indication of a transition of the cubic phase to a lamellar crystalline phase due to evaporative cooling. (d) with N2 as co-flowing gas and no visible birefringence. Scale bars, 100 μm.
