Autoclaving DNA and contamination

Brian Foley brianf at
Wed Jun 22 14:19:35 EST 1994

Duncan Clark (Duncan at wrote:
: If you all reckon that autoclaving is of no help to reducing PCR 
: contamination by 'trashing' the DNA then how should one prepare 10x PCR
: buffers and MgCl2 stocks. I have produced over 50,000 1.5ml buffers for
: various retailers (including licensed) of Taq pol etc over the last 3 years
: or so. They have all been autoclaved and so far there hasn't been one 
: reported case of false positives. Autoclaving is a pain but 
: sterile dispensing would be even worse. 
: -----------------------------------------------------------------------------
: Duncan Clark                        | Internet:    duncan at
: GeneSys Ltd.                        | Compuserve:  100015.1406 at
: -----------------------------------------------------------------------------

	Autoclaving is great if the buffer or solution is not 
contaminated with DNA to begin with.  The autoclaving will sterilize
the solution, thus preventing bacteria from growing up and synthesizing
	I would think that if you are making these large batches of
buffers for PCR, you are taking care not to use flasks that were previously
used to harvest DNA.
	On the other hand... if I had a solution in my lab that somehow 
got contaminated with a plasmid, and I needed to cure that solution of 
such contamination, I would not trust autoclaving to do the job.  UV
light would probably work better.  But the real solution is to prevent the
contamination in the first place.

*  Brian Foley               *     If we knew what we were doing   *
*  Molecular Genetics Dept.  *     it wouldn't be called research  *
*  University of Vermont     *                                     *

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