Alternative for PD-10 columns?

[WS]

Dear Experts,

is there any commercial (and preferably cheaper) alternative to PD-10
desalting columns?
(They are filled with Sephadex G-25, sample volume is up to 2.5ml,
elution volume is 3.5ml).

Many thanks fpr your help,

Wo

[Nick Theodorakis]

On Feb 2, 5:26 am, WS <novalidaddr...@nurfuerspam.de> wrote:
> Dear Experts,
>
> is there any commercial (and preferably cheaper) alternative to PD-10
> desalting columns?
> (They are filled with Sephadex G-25, sample volume is up to 2.5ml,
> elution volume is 3.5ml).

Buy the empty disposable columns and fill them yourself.
Alternatively, if you can work with low (100 ul) volumes, you can pour
them in 1cc syringes and do spin-column desalting.

Nick

--
Nick Theodorakis
nick_the...@hotmail.com
contact form:
http://theodorakis.net/contact.html

[Michael Sullivan]

On Feb 2, 2010, at 6:16 AM, Nick Theodorakis wrote:

> On Feb 2, 5:26 am, WS <novalidaddr...@nurfuerspam.de> wrote:
>> Dear Experts,
>>
>> is there any commercial (and preferably cheaper) alternative to PD-10
>> desalting columns?
>> (They are filled with Sephadex G-25, sample volume is up to 2.5ml,
>> elution volume is 3.5ml).
>
>
> Buy the empty disposable columns and fill them yourself.
> Alternatively, if you can work with low (100 ul) volumes, you can pour
> them in 1cc syringes and do spin-column desalting.
>

One doesn't even need to limit oneself to a small volume. I've run
spin columns with 3 and 5 mL syringe barrels. I've found I can easily
apply up to 1/3 of matrix volume, get good recovery and good
desalting. Details of my column procedure can be found in Crop
Science 46:662-670 (2006).

Mike

> ---

Michael L. Sullivan
Plant Research Molecular Geneticist
US Dairy Forage Research Center
ARS-USDA
1925 Linden Drive West
Madison, WI 53706
(608) 890-0046 (Phone)
(608) 890-0076 (FAX)

[Arne K Christensen]

Depending on your application, you may consider filter concentrators or
dialysis.

If you're using the columns to desalt or buffer exchange your sample,
you could use a centrifugation concentrator with a molecular weight
cutoff just below your protein (or whatever) of interest. Concentrate,
then dilute your sample with your new buffer... concentrate, then dilute
your sample with your new buffer.

Corning Spin-X Ultra Filtration Concentrators

http://www.fisher.co.uk/offers/index.php?pid=354

Alternatively, you could use dialysis membrane, and dialyze your sample
several times against your new buffer. Much cheaper.

> _______________________________________________
> Methods mailing list
> Met...@net.bio.net
> http://www.bio.net/biomail/listinfo/methods
>
>

--

__

Arne K Christensen

Postdoctoral Research Associate
University of Massachusetts, Amherst

USGS Conte Anadromous Fish Research Center
One Migratory Way, PO Box 796
Turners Falls, MA 01376

Email: ar...@bio.umass.edu
Phone: (413) 863-3827
Fax: (413) 863-9810
URL: www.biobog.com

[WS]

Many thanks for your suggestions so far!

I forgot to mention that (except to my normal behavior in the methods
+reagents realm where I like to suggest homebrew), this time I am in
need of a solution that does not require any calibration etc. etc. I
need reproducibility. I wondered if there was any commercial
alternative to PD-10, preferably even of the same dimensions (although
this wouldn't be a problem as long as they are similar scale and have
a frit on top). I searched the web, of course, but haven't found any
alternative. .

Wo

[wat...@googlemail.com]

You could also try Ammonium sulfate precipitation of your protein and
then resuspend the pellet in your buffer of choice.