title: GSM3031511: K562_AID-BRD4_Pol2-S2P_DMSO; Homo sapiens; ChIP-Seq
library_construction_protocol: Cells were cross-linked with 1% formaldehyde (10', RT). Nuclei were isolated, lysed, and chromatin was sheared by sonication. Mouse chromatin (ratio 10:1, human:mouse) was added for internal normalization. Antibodies against total Pol2, Pol2-S2p or Pol2-S5p (active motif) were added overnight at 4° and captured with magnetic sepharose beads for 2h at 4°C. Beads were washed, immune complexes eluted, and cross-links reversed for 6h at 65°C. Genomic DNA was recovered by phenol-chloroform extraction and ethanol precipitation. Deep sequencing libraries were prepared using the NEBNext Ultra II DNA Library Prep Kit for Illumina.