[Rasmb] Tween 80 effect

[Yi-Ming_Li at hgsi.com]

Hi:
I think that the discussion (initiated by Qin) on the effect of Tween 80
(T80) is very helpful, since T80 is commonly used in the formulation of
many drug proteins. The best way to avoid the problems, as suggested by
Peter, is not to use T80 in the running buffer. But in many cases, bulk
drug substances are already in the formulation containing T80. It can bind
to many proteins so it cannot be removed completely. I think that we maybe
able to reduce the interference of Tween 80 by using a running buffer with
Tween concentration much lower than its CMC. With this approach, the
interference of Tween 80 can be reduced through the following mechanisms:
1) T80 signal becomes much less relative to protein signal.
2) T80 concentration can be made exactly the same in reference and in
sample by extensive dialysis, since below CMC,  T80 molecules can go across
    dialysis membrane easily.
3) Without forming micelles, the distribution of T80 molecules should be
less sensitive to centrifugational force and therefore, they distribute
"more evenly"
     in the sectors. It is better for canceling the T80 signals.

Thanks!

Yi-Ming Li