Using TdT to clean up sequencing reactions?

drdad at drdad at
Tue Aug 20 18:10:55 EST 1996

In article <edwardm-2008961504110001 at>,
edwardm at wrote:

>    Recently a company sales rep told me that really clean sequencing gels
> that are produced from various companies are cleaned up using TdT.  This
> enzymes apparently can add lots of nucleotides to the newly synthesized
> DNA strands that are not terminated by the dideoxy nucleotides in the
> mixes.  Thus those annoying stops in all four lanes are eliminated because
> the ssDNA never really runs into the gel.
>    My questions is: Does anybody have a protocol for how this is done?


I've tried the TdT technique and really prefer the Klenow co-sequencing
method referred to in Biotechniques Vol 17, pg. 286 (1994). I use this as
part of my routine sequencing protocol now.

Good luck!

Felix Guerrero
drdad at

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