Lysates were clarified from sonicated nuclei and histone-DNA complexes were isolated with polyclonal αWOC, αROW, αZ4, αDsk2 and αHP1c antibodies. Finally DNA was purified by standard phenol extraction. 10 ng DNA, quantified by Qubit dsDNA HS Assay Kit (Invitrogen) was used for library preparation. Endrepair, adenylation, ligation of adapters and PCR enrichment for 18 cycles was performed using TruSeqRNA Sample Prep Kit (Illumina) according to manufacturer’s recommendations. Purified libraries were quantified by Qubit dsDNA HS Assay Kit (Invitrogen) and size distribution was evaluated using Bioanalyzer DNA 1000 assay (Agilent).