Protein separation via ion-exchange chromatography

Nick Theodorakis nicholas_theodorakis at
Tue Jul 11 08:14:52 EST 2000

Brett <Brett.Oconnell at> wrote:
>I intend to separate some proteins by DEAE sephadex
>ion-excheange chromatography.  My concern is this:
>I have not found any theory regarding the relationship
>between the concentration of the sample to be applied
>to the column and the dimensions of the column.
>My sample is quite dilute (~0.35 mg/ml total protein in
>about 9 ml). Can anyone give me some insight into the
>appropriate column size I should be using?  Does the
>sample concentration matter?

To a first approximation, the total amount of protein is more
important than sample concentration for determining column size.
Indeed, some people have used ion-exchange to concenrate
There is usually soem info on the binding cpapcity of the resin
you are using on the 'spec sheet.

>As an aside, I am wondering how many people actually
>read these bionet newsgroups since they tend to be quite
>empty.  Is this because people read but don't post, or
>because the answers to the questions that are asked are
>too obscure for those who do look through bionet??
>I'm just concerned that I'm throwing my question out to
>only about 10 people or something.... So if anyone knows
>of a place I might be more likely to get a response, that
>information would also be much appreciated.

bionet.general is pretty quiet, but more useful groups are
bionet.molbio-methds-reagnts and bionet.proteins.

As for protein purification, Pharmacia used to sell (or even
sometimes give away) booklets on ion-exchange and gel filtration
chromatography that were quite useful. I don't if they still do
(and they are owned by Amersham now), but it might be worth a
to see if they still have them. Also, there used to be a book by
Scopes, called something like, "Principles of Protein
Purification." (I don't remember the exact name; people used to
just call it "Scopes")

Ah, here it is; I just looked on Amazon:

Protein Purification: Principles and Practice (Springer Advanced
Texts in Chemistry)

by Robert K. Scopes, Charles R. Cantor (Editor)

It looks like it's still in press and even updated.


Nick Theodorakis

nicholas_theodorakis at


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