GSM1319308: H2AKll9ub; Homo sapiens; ChIP-Seq
Chromatin immune precipitation (ChIP) was essentially performed as described previously (Frank et al., 2001). Briefly, K562 cells were transduced with the lentiviral GFP-fusion vectors encoding GFP-CBX2, PCGF1-GPF, MEL18/PCGF2-GFP, BMI1/PCGF4-GFP, GFP-RING1A or GFP-RING1B. K562 cells expressing GFP-fusions at relatively low levels were sorted and expanded and subsequently crosslinked. ChIP reactions were performed using the following antibodies: anti-GFP (ab290, Abcam), anti-H3K27me3 (07-449, Millipore),  and anti-H2AK119ub (D27C4, Cell Signaling Technology). ChIP efficiencies were determined by qPCR. Sequencing samples were prepared according to the manufacturer's protocol (Illumina). End repair was performed using the precipitated DNA using Klenow and T4 PNK. A 3’ protruding A base was generated using Taq polymerase and adapters were ligated. The DNA was loaded on gel and a band corresponding to ~300 bp (ChIP fragment + adapters) was excised. The DNA was isolated, amplified by PCR and used for cluster generation on the Illumina HiSeq 2000 genome analyze. ChIP seq libraries were preapared according to  Illumina's standard protocol.