EpiSCs were grown in feeder-free conditions in fibronectin (Millipore) coated dishes. Culture media contained: N2B27 medium supplemented with bFGF (12 ng/ml) and ActivinA (20 ng/ml). 20 ng of immunoprecipitated or input DNA was used for library preparation using Ovation Ultralow DR Multiplex System (0331, Nugen). Once prepared library DNA was resolved on a 2% agarose gel and the dinucleosome fractions were isolated