purefication and amplification of serum free DNA - (Jul/22/2009 )

Hi all,
I'm trying to purify short DNA fragments from human sera (free DNA) and amplify this fragments
I'm using phenol:chloroform:isoamil for purification but when i try to amplificate the
fragments by using TdT for tailing at the first step and PCR afterwards with the right primers for the tails,
for some reason I didn't succed in the amplification (or the purification)
I'll br glade if you can help

Sincerely
Rami

Hi Rami,to clarify your procedure is working add a know amount of short DNA fragments to human sera and try to do the same procedure purify and amplify it. In this way you can narrow down the problem.

And it will helpful to reply if you give more details about your protocol this details is not sufficient.