title: mouse activated PolII, AID-E1 deletion , PolII rep2
design: Cultured cells were fixed with 1% formaldehyde (Sigma) for 10 minutes at 37*C followed by quenching with glycine and sonication.  Fragments were immunoprecipitated with an anti-PolII (PolII 4H8 ab5408) antibody following standard protocols and processed according to Illumina's standard protocol.