You could try loading a small 1ml HiTrap (or similar) Q or S column with your protein - and knocking it off it in one go with high salt, alternatively micro-dialysis against a solution containing PEGs can also work well.
Tony Sent from my iPhone On 21 Jul 2011, at 17:54, "Narayanan Ramasubbu" <ramas...@umdnj.edu> wrote: > Dear All: > We have been trying to crystallize a protein which is large - > 100 kDa. This > is soluble but the best we can get is about 1 mg/mL. > It did crystallize but did not diffract well. Efforts to increase the > concentration has been unsuccessful. I am wondering whether there are methods > that others use to increase the concentration other that using amicon columns. > Any help will be appreciated. > Thanks > Subbu
