Damn those chickens!

[bbeitzel at biomail.ucsd.edu]

I have been trying to sequence chicken DNA using an ABI automated
sequencer, but I have been having a lot of problems.  It seems that no
matter what fragment of chicken DNA that I try to sequence, I always hit a
poly-G or poly-C tract about 200-300 nucleotides into the sequence.  The
Taq polymerase used in these reactions really doesn't like those
sequences, and the sequencing reaction is "killed."  I have tried making
primers very close to these regions to try and "blast-through," and have
tried both DMSO (a couple of times,) and betaine (once,) to no avail. 
Does anyone out there have any tricks for getting through these poly G or
poly C stretches?

Thanks for any info,
Brett Beitzel

-- 
Brett Beitzel
bbeitzel at biomail.ucsd.edu

Infectious Disease Lab
The Salk Institute
La Jolla, CA