Isolation of "hot" oligos

Suzy Paalman suzy at
Sat Jun 15 19:49:43 EST 1996

In article <kremers-1306961122030001 at>,
kremers at (Joachim Kremerskothen) wrote:

> Hi netters,
> we have a problem with the isolation of radioactive-labeled oligos
> (20mers) after T4 kinase phosphorylation. Ethanol precipitation and gel
> filtration with Pharmacia`s G50 columns didnt work very well (maybe
> because of the lenght of the oligos?). Are there other and better methods
> for the isolation?
> -- 
> Dr. Joachim Kremerskothen
> Institut for experimental Pathology
> University of Muenster
> Mendelstrasse 11
> D-48149 Muenster
> Germany
> phone ++49 251 838615
> fax ++49 251 838616


I routinely label and purify 20mers.  The two methods I use to get rid of
free label are G-25 columns (as someone else suggested, G-50s won't work
for 20mers) and ethanol precipitation with 10mM MgCl2 as the salt (if
possible-I use sodium acetate if I've inactivated the kinase with EDTA) and
using linear polyacrilimide (available from Sigma) as the carrier.  Both of
these methods work well for me.


Johns Hopkins School of Medicine

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