Precipitation of Native Protein - IMAC of Native Protein (May/04/2002 )

Hi,
I´m purifying a His-tagged protein under native conditions via IMAC (Talon). While eluting (400mM Imidazole; 150mM KCl; 20mM Tris-HCl; 0.05% Triton X-100) I get precipitations and the concentration of protein in solution is quite low. Any ideas how to enhance solubility under native conditions (detergents, concentrations)?

Thanks,

robdom

If you can, check the isoelectric point (IEP) of your protein. If it stayed in solution before this step, it could be that the changed pH is the culprit. Proteins have lowest solubility at their IEP.