gelfiltration on superdex 75 pg

[Richard P. Grant]

In article <39D36691.D21C4C49 at vub.ac.be>, Sigrid Van Boxstael 
<svboxsta at vub.ac.be> wrote:

> I can only recuperate 1.5 mg in the obtained peak.
> The buffer I used : Tris 20 mM pH 8.2, 2 mM mercapto-ethanol, 150 mM
> NaCl.
> When I clean the column after the run there is coming protein of it.
> I presume that my protein sticks on the column.

Is the column calibrated?  Is the 'obtained peak' in the correct place - 
are you *sure* it's not running in the void volume?  Where do you see 
the contaminating protein?

If a fraction of your protein aggregates it could barrel through and 
come out first - with you thinking it's the main peak.

-- 
Richard P. Grant MAD Phil      http://www2.mrc-lmb.cam.ac.uk/personal/rpg/ 

Please reply to rpg 'at' mrc-lmb.cam.ac.uk'