DEAE Sepharose "clumping"

[D.K.]

On Wed, 22 Dec 2004 13:32:08 -0600, "Andor J Kiss" <akiss at life.uiuc.edu> wrote:

>Hello,
>
>    I have a problem with some DEAE Sepharose FF that has clumped.  I've 
>tried regenerating it, tried high salt (2M NaCl) tried neutral buffer, 
>neutral buffer + high salt.  Nothing seems to work.  Amersham tech support 
>is terrible.
>
>Any suggestions?

Yes. You are dealing with the [mostly denatured] proteins stuck 
hydrophobically to the matrix.  High salt is of no use here. Try 6 M GuHCl or
0.5-1.0 M NaOH. No harm even in using 0.5 M NaOH + 0.5% SDS. The only 
trick is to wash the sepharose extensively after that to get back to the ~
neutral pH and wash out traces of SDS. 

DK