 |
 |
Superdex 200 instruction manual suggests a minimal 150mM NaCl is required to prevent binding of protein to the resin. But it seems more to the side of preventing loss of protein instead of misjudging protein size. Nian Huang, Ph.D. UT Southwestern Medical Center On Tue, Mar 22, 2011 at 7:23 PM, Jacob Keller <[log in to unmask]> wrote: > Dear Crystallographers, > > I have run my protein-peptide complex several times on a GE S200 > 10/300 in buffer A (below). Today, to make a crystallization stock, I > ran the sample in buffer B, and the peak shifted from a consistent > 16.0 mL to 13.5mL, which would seem to be ~dimer MW, but I know that > SEC results change as a result of buffer conditions. Could this > drastic a shift be due simply to buffer conditions, or could there > actually be some buffer/ion-dependent dimerization going on? Anyone > have a similar experience? > > A: (20mM HEPES, 50mM NaCl, and 5mM CaCl2 pH'd to 8.1 w/ TRIS base) > B: (5mM HEPES, 0mM NaCl, and 1mM CaCl, pH'd to 7.5 w/ TRIS base.) > > Jacob Keller > > ******************************************* > Jacob Pearson Keller > Northwestern University > Medical Scientist Training Program > cel: 773.608.9185 > email: [log in to unmask] > ******************************************* >