🚀 go-pugleaf

Because PEG is a linear molecule, it actually has a Stokes radius much
higher than the pore size of the dialysis tubing. The pore size I
believe is determined useing globular molecule. Many years ago I tried
to dialyse residual PEG OUT of a protein solution (PEG 8000, Tubing
12-14 K cutoff) and came back the next day to tubing swollen to 10 times
it's normal diameter. It looked (and acted) like a water ballon. You
should have few problems except for the protein sticking to the tubing.
An alternative is to dialyse against a vacumm. But this also has the
same sticking problem.

Good Luck

Jim Kami
Blue Rose Biotech


Louis Hom wrote:
> 
> I have a protein solution I need to concentrate and I'd like to use
> dialysis tubing and dry PEG.  The only problem is, I don't have any PEG
> with a MW higher than the cutoff for the dialysis tubing (12-14kD).  Can I
> use polyvinyl alcohol instead (MW supposedly around 70kD)?  Thanks.
> --
> _______________________________________________________________________________
> Lou Hom >K '93
> lhom@nature.berkeley.edu
> http://www.ocf.berkeley.edu/~lhom