“…Histone extraction and derivatization were performed as described previously [ 23 , 40 , 41 ]. Nuclei in wash buffer (75 mM NaCl, 10 mM EDTA, 50 mM Tris-HCl pH 8.0) were centrifuged at 3000× g and 4 °C for 10 min, incubated in nuclei lysis buffer (50 mM Tris-HCl, 100 mM NaCl, 3 mM EDTA, 1% CHAPS) supplemented with protease, deacetylase, and phosphatase inhibitors (0.1 mM PMSF, 45 mM sodium butyrate, and 10 µL/mL protease inhibitor cocktail (P9599, Sigma-Aldrich) and 10 µL/mL phosphatase inhibitor cocktail (P5726, Sigma-Aldrich)) for 1 h on ice, spun at 10,000× g for 5 min, washed with 50 mM Tris-HCl, and spun at 10,000× g for 5 min.…”