Temp. Gradient Gel Electrophoresis/GC clamps

M K Bennett pamkb at mail.bris.ac.uk
Wed Mar 22 04:13:16 EST 1995

MARLENE SNYDER (msnyder at ace.acadiau.ca) wrote:
: I am trying to figure out just how TGGE works, and why the GC clamp 
: facilitates TGGE detection of single base substitutions within a fragment.
:  It  seems to me the clamp would prevent melting, but melting is what is
: desired,  isn't it?  What am I missing here...

Its quite straight forward really.  The clamp is designed to be the last
part of the molecule that will melt, so all the regions in the DNA of
interest will have melted before the clamp.  This gives you the maximum
chance of finding any polymorphisms in your DNA.  If you dont use a clamp
then there is the chance that the whole of your sample DNA will melt and
you will lose the DNA off of the bottom of the gel before getting to
resolve any differences between your samples.

mail me if you are still confused.

Mike Bennett D.Phil		|Scientists have odious manners, except when
Dept Pathology and Microbiology,|you prop up their theory; then you can borrow
University of Bristol, UK	|money from them--Mark Twain 1917 
m.k.bennett at bristol.ac.uk	|

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