Using DS DNA as a primer

[Kajetan Groicher]

Hello All-

Well here is one we have been struggeling with...

A fellow Grad Student of mine is attempting a PCR reaction in which one
of the primers is actually a DS DNA fragment which had been purified
earlier.  Upon running the rxn we get various non-specific products, and
a REALLY low amount of the expected size product, not enough to be of
use.

The Pol we are using is vent, we have tried w/both MgCl2 and MgSO4,
various conc. of course.

And the DS primer is ~325bp in length.  We have tried to vary the
Tanneal within a 15 degree range.

So my question is, has any one tried using a DS DNA frag as a primer,
and if so, how did ya get it to work.

Any help or insight would be greatly appreciated.  Thanks in advance

Kajetan