Desalting of Plasmid DNA after Cesium Preps

[Kent S. Boles]

>Rather, I suspect the dialysis membrane adsorbs quite a lot of DNA (I
>definitely *know* for protein samples; if you don´t believe, just dialyse any
>protein you want against any buffer, then take out the sample and wash the
>membrane with buffer. Then, cut the membrane to pieces, boil them in SDS
>sample buffer and apply to a gel. You´ll be shocked...)

I hadn't thought of this possiblility. A good way to test this would be
to drop the sealed tubing in an eletrophoresis aparatus and reverse the
field back and forth a couple of times. It should effectively knock the
DNA off the membrane. Might be interesting to compare side by side.
Just a thought.
Have you ever tried to convince a Qiagen rep that CsCl is better for
removing endotoxin than their reagents?
Cheers,
Kent
-- 

Kent S. Boles
Department of Molecular Biology and Immunology 
UNT Health Science Center at Fort Worth 
3500 Camp Bowie Blvd 
Fort Worth, TX 76107
kboles at removethis.hsc.unt.edu
817-735-5045 voice 
817-735-2118 fax