Mark Olson wrote: > > Actually, I ran a test sample using a 40kd cut off Millipore > centrifugal tube/filter. The SDS revealed the GST didn't go through, > it just stayed in solution with my fusion protein. I guess something > is preventing the GST from going through the membrane. I wonder if I > need to use a high salt buffer to spin the sample in. > GST is a dimer.