After removal of IRMEFs, iPS cells were collected after washing with PBS. Then cells were subjected to crosslinking in 1% formaldehyde (Thermo scientific, 28906) for 10 minutes at room temperature, followed by the addition of glycine at the final concentration of 0.125 M to quench the reaction. After centrifuge, cells were washed with cold PBS, counted and pelleted as 10 million cells for each nuclei preparation. The nuclei were isolated and prepared for shearing using TruChIP chromatin shearing kit (Covaris, 520127) according to manufacturer's protocol. After shearing, ChIP was performed using the iDeal ChIP-seq kit (Diagenode, C01010051). The antibodies used were: anti-H3K4me3 (Diagenode, C15410003-50), anti-H3K4me2 (Abcam, ab7766), anti-H3K4me1 (Abcam, ab8895), anti-H3K9/14ac (Diagenode, C15410200), anti-H3K27ac (Abcam, ab4729), anti-H3K36me3 (Active Motif, 61101), anti-H3K27me3 (Active Motif, 39155), and anti-CTCF (Active Motif, 61311). After de-crosslinking, DNA was extracted using MinElute PCR-purification kit (Qiagen, 28006) or Agencourt AMPure XP beads (Beckman Coulter, A63881) and subjected to library preparation using NEBNext ChIP-Seq Library Prep Master Mix Set for illumina (NEB, E6240L). The ChIP experiments and library preparation for antibodies including anti-RNA polymerase II (Abcam, ab5095), anti-Brd4 (Bethyl Laboratories, A301-985A) and anti-H3K9me3 (Active Motif, 39161), were performed by Active Motif.
GEO Accession
GSM2949106