Fig. 4
Microscopy images (10\(\times\) magnification, NA 0.28, pixel size \(\sim\)1.26 µm) showing PSII crystal delivery in medium-viscous buffers on the SPB/SFX instrument using a DFFN. The interaction position with the X-rays is indicated with a red arrow. The images show crystal-laden buffer surrounded by ethanol (a, proposal no. 3333) and the viscoelastic shell (b, proposal no. 8756). The jets (djet \(\sim\) 4 µm) were generated with \(Q_i=25\) µL/min and \(Q_o=40\) µL/min (a) and \(Q_i=20\) µL/min and \(Q_o=10\) µL/min (b), respectively. The mass flow rate was \(\dot{m}_g=30\) mg/min (a), and 19 mg/min (b), respectively. While the EtOH-sheathed jet wiggles strongly, the PEO-sheath enables a long and steady jet. Table 4 compares the hit rate statistics.
