Samples for HiC library construction
Briefly, intranuclear chromatin was fixed with formaldehyde, and the cross-linked DNA was subjected to restriction digestion using the DpnII enzyme. The sticky ends were repaired to blunt ends with biotin-marked nucleotides, and the blunt ends were ligated with DNA ligase. Following protease treatment for protein removal, the purified DNA was fragmented into 300 bp average-sized particles via sonication and ligated to adapters.  Biotin-labeled DNA fragments were then captured and enriched using streptaxin beads.