Hi MWt PCR artefact

Dr. Duncan Clark drc at nospam.demon.co.uk
Fri Jul 14 03:51:50 EST 2000


In article <396E5B9F.1F37451A at uow.edu.au>, Mark Dowton
<Mark_Dowton at uow.edu.au> writes
> I would guess that
>it's a bona fide PCR product, but it is far too big (>20 kbases)  to be
>produced in the 2.5 min extension we're giving this (we do have a
>Taq/PFU polymerase mix though). It only appears with ca. 3 mm Mg++ in
>the PCR reaction, much less is produced with 1 mm.  Any ideas?

It will be DNA but I have no idea why it appears. You can get this,
usually as a smear, when doing long PCR. Anything from 100bp right the
way back to the well. There has been a couple of papers in NAR maybe 2
years ago about Taq and Tth being able to do de novo DNA synthesis i.e.
no template or primers in the reaction. No reference to hand.

Duncan
-- 
The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

Duncan Clark
DNAmp Ltd.
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http://www.dnamp.com
http://www.genesys.demon.co.uk






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