Need ion exchange HPLC col's

mcada002@mc.duke.edu
Fri, 17 Sep 1999 09:18:45 -0400

Can anyone recommend HPLC col's and buffers for purification of 50 to 100 mg of
peptides via ion exchange.
Presently I need to purify two very short synthetic peptides (4 AA's). They
will not interact (i.e., they wash through) with my C18 Reverse Phase columns in
either 0.1%TFA, 0.1%HFBA, or 50 mM NH4HCO3. Sequence is NH2-Arg-Gly-(Asp/or
Glu)-Ser-OH. Mol. Wt's 433.5 and 447.5.

I have also had much difficulty with very long (30 AA's long), Asp/Glu rich
peptides that did respond better with the 50mM NH4HCO3 and C18 column. But
these shortties are just not gonna cooperate.

Help, Help Help.

Thanks.

Millie
mcada002@mc.duke.edu
919-684-2652
919-684-5458 FAX