Before soaking, all crystallization drops wells were inspected using the TeXRank program and the most promising drops were selected. Furthermore, the coordinates for the compound solution dispensation were selected, in order to avoid dispensing the compound solution on top of the crystal, something that could have damaged our crystals. An acoustic dispenser (ECHO liquid handler) was used to dispense 75 L of compound solution (500 mM stock solution in DMSO, 100 mM final concentration) to the targeted coordinates of each single crystallization drop and let to soak for up to 2 hours at room temperature. In total, 875 compounds from the DSi-Poised library and 102 compounds from the Leeds-3D library were used for soaking. This resulted in 973 crystals which could be harvested and mounted for diffraction using the OLT crystal shifter. Diffraction data were collected at 100 K at the I04-1 and I03 beamlines.