pI=9.5 protein will not bind to cation exchanger at pH 6.5

Bipin K Dalmia bipin at iastate.edu
Tue May 3 17:38:03 EST 1994

i'm trying to purify a protein expressed in e. coli. there is tons of it
in the soluble extract. the pI is about 9.5. so naturally i tried using
a cation exchanger at pH 6.5 but my protein flows right thru it. i've
checked the ionic strengths etc. and they look good. the resin was
properly equilibrated too. i'm using bio-rad's biorex-70 resin in the
sodium form and eluting with a gradient of NaCl. 

any clues?

bipin k. dalmia               the other night i was lying on my bed, looking
bipin at iastate.edu             up at the beautiful stars, and i said to myself, 
n2.bkd at isumvs.iastate.edu     'where the F*CK is my ROOF !!'

More information about the Proteins mailing list