Ionic interactions on Sephadex G-10

dmb618 dmb618 at enh.nist.gov
Mon Jan 23 17:49:29 EST 1995


In article <3ffhms$m7s at dingo.cc.uq.oz.au>, J.Marcus at tpp.uq.oz.au 
says...
> 
> : Ionic interactions on Sephadex G-10
>
>According to Phamacia, ionic interactions on Sephadex G-10
>are due to the fact that the cross-linked dextran chains contain
>a few terminal carboxyl groups; the gel will therefore act as a 
>weak cation exchanger with very low capacity.
>
>To remove these effects, it is suggested to use an ionic strength
>of 50mM in the eluent buffer.
>
>I want to desalt low molecular weigth peptides (1000-5000Da) using
>G-10 Sephadex.  My problem is that I don't want any buffer at all 
>in the eluent.  The proteins I am desalting are quite basic so I fear
>that some might interact with the column packing if I were to totally
>do away with buffer.  Ideally, I would like to use straight deionized
>water to elute the proteins from the column.
> 

>Sincerely,
>John Marcus

If you are trying to isolate your peptides salt-free, why not just a volatile 
buffer such as ammonium acetate for your gel filtration and lyophilize the 
fractions containing the peptides?

-David




More information about the Proteins mailing list