Libraries were made using the Truseq DNA sample prep kit (Illumina). 1-10ng of ChIP or 10ng of input are blunted (T4 polymerase), an A-overhang is added (Klenow), DNA is ligated to adaptors, amplified by PCR, and the library size-selected to a 250-400 bp range using Agencourt AMPure XP beads.