Maybe your old solution evaporated then you end up in your old tube with a more concentrated solution in PEG and NaCl so try to screen with new conditions with higher PEG and/or NaCl concentration....
Mick 2011/4/12 Jun Yong Ha <j...@princeton.edu> > Hi all, > > Recently, I produced crystals with MBClass1-64 which contains PEG4000, > HEPES-Na and NaCl. But, I struggled to reproduce crystals. I tried to set up > tray with different batch of solution. I got the crystals only from 2008 > solution, but not from fresh ones. I asked technical service of Qiagen, but > they did not have any stock. > > pH between fresh and old solution is the same. I could reproduce crystals > with this old solution 100% when setting up. > > Do you have any experience like this? Is PEG4000 degraded or oxidized? > > Please help me. > > Thanks in advance. > -- ------------------------------------------ Mickael Blaise PhD Department of molecular biology Centre for structural biology Aarhus university Gustav wieds vej 10 8000 Aarhus-Denmark
