my his-tagged protein has a theoritical pI of 7.02.
So far, after expression in Origami, I've denatured the bacterial pellet in 6M urea/0.5M NaCl/20mM tris pH7.9.
I first tried a sequence of dialysis: 4M urea/PBS, 2M urea/PBS, then PBS. from 2M to PBS only, the protein precipitates.
Should I change the pH of my buffer?
any advice on stopping this precipitation?
Many thanks in advance.
Edited by vblanche, 08 April 2010 - 05:59 AM.