DNA prep from Serum - trying to isolate small fragments of DNA in human serum (Sep/12/2006 )

This is a highly debated topic, but i was curious if anyone here has had any substantial progress on DNA extraction from human serum samples.

I can get small quantities of short fragmented DNA, which I can easily PCR. It's just hard to tell the quality of the dna. I'm trying to avoid isolating any white blood cells.

hrm. i wanted to explain my question a little more.

Yes you can get DNA out of serum, but what is the DNA from?

apoptotic cells?
epithelial?
white blood cell fragments?