Hi Jobi Sounds like you need to explore your protein vs PEG concentration, and my guess (directly contradicting Artem's) is that chances are you need to pump [protein] way up and drop [PEG] way down. Like in [protein]=>30-40mg/ml, [PEG]<=2-4%. Often people don't go into that range when setting up optimizations, because the original condition was, say, 25% PEG. But looking at the solubility curve, this is the regime where few nuclei form and then have lots of protein to grow with. phx.
_____ From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Jobichen Chacko Sent: 30 March 2007 00:45 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Multiple nucleation Hai All, Sorry for the non Ccp4 question. I got very small crystals for a protein and I am trying to optimize the condition to improve the size of the crystal and reduce the number of nucleation. The crystals are coming from five to six conditions , all have PEG 3350 in common. Apart from PEG, the condition has Lithium sulphate and Bis Tris in one condition and Ammonium suphate and HEPES in another condition, while the third condition is Sodium malonate, Bis Tris and PEG. I am getting thousands of small crystals with some precipitation. I tried macroseeding and additive screen, but the crystals are not growing. Any suggestions are more than welcome. Thank you. Jobi
