Nuclear isolation by hypotonic buffer and mechanical lysis followed by centrifugation in 0.3M sucrose buffer. Isolated nuclei were crosslinked in 1% formaldehyde for 10 minutes, quenched with 137mM glycine for 5 minutes, lysed in denaturing buffer (50 mM Tris pH 8, 1 mM EDTA, 0.5 mM EGTA, 0.1% Na-deoxycholate, 0.5% N-lauroylsarcosine, 150 mM NaCl and Protease Inhibitor Cocktail) and sonicated by 30x30 second cycles in the Bioruptor Pico (Diagenode B01060010). NEBNext® UltraTM Library Prep Kit for Illumina with 12 cycles using dual index oligos for Illumina (New England Biolabs, E6440S)