title: GSM3456988: BRCA1_WT1; Homo sapiens; ChIP-Seq
library_construction_protocol: Harvested cells were washed with PBS, fixed with 1% formaldehyde for 10 min, quenched with 0.125 M glycine for 5 min at room temperature, and washed twice with PBS. Fixed cells were pelleted, flash frozen, and stored at -80°C for further processing. Crosslinked cells were lysed with lysis buffer (1% SDS, 50 mM Tris-HCl, pH 8.0, 20 mM EDTA, 1x complete EDTA-free protease inhibitor (Roche)) on ice for 10 min, diluted with TE buffer, then sheared using a Branson Tip Sonifier 450 on ice (15 cycles, 15s on, 45s off/cycle at power 3). For bead preparation, Protein G Dynabeads (Life Tech) were incubated with 3 ug of H3K27ac pAb (31933, Active Motif) overnight at 4°C. Incubated beads were washed 3 times with PBS with BSA. Detailed protocols for immunoprecipitation and library preparation are available on the ENCODE homepage.1,2