Cloning pg amouts of DNA?

[Seth Daniel Crosby]

I have developed a technique for immunoprecipitation of chromatin
using an anti-transcription factor polysera.  It works well as
indicated by PCR detection of a known target gene.  I would like
to clone other fragments in order to determine other candidate
target genes.  

The problem is the technique yields picogram quantities of DNA.
How do I clone vanishingly small amounts of chromatin!?