GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2005-08 > 1124235394
Subject: Re: [DNA] DHPLC??
Date: Tue, 16 Aug 2005 19:36:34 EDT
In a message dated 08/16/05 9:07:59 AM Pacific Daylight Time,
> I recently read that the "DHPLC" typed some dna samples, etc. What is the
Denaturing High Performance Liquid Chromatography. Very briefly, when DNA is
heated, the complimentary strands separate (denature). When cooled again, they
"anneal," returning to the double helix form with complimentary bases as
expected. If the solution contains a mixture of DNA, with one sample differing
slightly from the other (e.g. a SNP is present), sometimes the wrong strands
match up when cooled (since they do match along most of their length). This causes
a "bubble" and makes the molecule migrate at a different rate.
I posted this URL for a graphic in my message on SNP hunting a while back.
This method can be used to test known Y SNPs by running the sample with a
control. Also, many DNA samples can be pooled and screened for polymorphisms as
part of SNP discovery. These samples cover a known location on the Y and are
several hundred bases long. Since SNPs are very rare (about every 10,000 bases
on the Y chromosome), a goodly proportion of the runs will have only
homoduplexes. The few pools which do contain heteroduplexes can then be examined more