Dear All, I have produced crystals from a robotic screen (API) in two conditions. However, I have not been able to reproduce them. They originally grew in 2.5 days (over the weekend, though it could have been sooner). I noticed that when I first set up the tray, these two wells were clear but when I reproduce the condition, I get immediate precipitation. Furthermore, in the original screen the two drops were smaller than the rest. I have tried different ratios of reservoir solution though I get less precipitation, the drops are not clear.
This brings me to my question. Could it be possible that the robot never dispensed the reservoir solution and the protein just crystallized against the reservoir solution through simple concentration? I have just set up a couple of drops just against reservoir solution. If this is the case, has anyone else experienced this and had luck with this and got diffraction? Thanks in advance, Dan
