Help: Desalting Oligos

Dr. Duncan Clark duncan at genesys.demon.co.uk
Thu Nov 21 11:55:50 EST 1996


In article <jabbott.1.32932B8E at biolsci.dundee.ac.uk>, JAMES ABBOTT
<jabbott at biolsci.dundee.ac.uk> writes
>Can anyone out there help me?
>
>We have some PCR primers which contain a high concentration of salt (Don't 
>ask - you'd only laugh!), which would appear to be precipitating PCR reaction 
>mixtures and preventing the reaction from proceeding. Does anyone know a 
>cheap and dirty method of desalting small quantities (200 nmol/ml) of oligos 
>(14mers-25mers) without too much loss of DNA.
>
>Thanks.
>

Ethanol pption using 2.5vols and no extra salt? 
G25 gel filtration or a G25 spin column.
Dialysis?
Dilute the salt even more with 10mM NaOH and load onto a monoQ FPLC
column (or similar). Elute with a salt gradient of 0.6-1.1M NaCl in 10mM
NaOH. Pool peak and ethanol ppt.

Duncan  
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Dr. Duncan Clark
DNAmp Ltd.
TEl/FAX 01252376288
http://www.prestel.co.uk/dnamp
http://www.genesys.demon.co.uk



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