GSM1423036: Pmel-shPTEN-H4K16AC; Homo sapiens; ChIP-Seq
Cells (5 million per antibody) were crosslinked using 1% paraformaldehyde for 10mins at 37 degrees. Reaction was quenched by 0.125M glycine for 5mins, cells washed with PBS and stored at -80oC. Next day cells were thawed on ice and lysed with RIPA buffer (10mM Tris-HCl pH 8.0, 1mM EDTA pH 8.0, 140mM NaCl, 1% Triton x-100, 0.2%SDS, 0.1% DOC) for 10min on ice. Sonication was performed using Branson Sonifier 250 to achieve shear length of 200-500bp. Antibodies were bound to dynabeads for 1 hr at 4oC. Extracts were then incubated overnight with antibody-dynabead mixture Immunecomplexes were then washed 5 times with RIPA buffer, once with RIPA-500 (RIPA with 500mM NaCl) and once with LiCl wash buffer (10mM Tris-HCl pH 8.0, 1mM EDTA pH 8.0, 250mM LiCl, 0.5% NP-40, 0.5% DOC). Elution and decrosslinking was performed in direct elution buffer (10mM Tris-Cl pH 8.0, 5mM EDTA, 300mM NaCl, 0.5% SDS) by incubating immunecomplxes at 65oC for 4-16hrs. Proteinase K (20mg/ml) and RNaseA treatment was performed and DNA cleaned up using SPRI beads (Beckman-Coulter). Libraries were prepared using NEB reagents as described earlier (Garber et al 2012). Briefly, DNA was end-repaired using a combination of T4 DNA polymerase, E. coli DNA Pol I large fragment (Klenow polymerase) and T4 polynucleotide kinase. The blunt, phosphorylated ends were treated with Klenow fragment (32 to 52 exo minus) and dATP to yield a protruding 3- 'A' base for ligation of Illumina's adapters which have a single 'T' base overhang at the 3’ end. After adapter ligation DNA was PCR amplified with Illumina primers for 12 cycles and library fragments of ~300-500 bp (insert plus adaptor and PCR primer sequences) were size selected by SPRI beads. The purified DNA was captured on an Illumina flow cell for cluster generation. Libraries were sequenced on the HiSeq2000 following the manufacturer's protocols.