Cells were fixed with 1% Formaldehyde. Nuclei was isolated and chromatin was fragmented. Chromatin immunoprecipitation (ChIP) was performed and the libraries was prepared using the eluted DNA from ChIP. Eluted DNA from ChIP was repaired to generate blunt 5' P ends using 'EndIT DNA End Repair kit' (Epicentre), 3' A overhang was generated using 'Klenow Fragment (3´→ 5´ exo-)' (NEB). Illumina barcodes were ligated using 'Rapid T4 DNA Ligase' (Enzymatics). Next libraries were size selected using 'Ampure beads' (Beckman Coulter) . After around 13 cycles of amplification, libraries were cleaned, quantified and pooled.