title: GSM4678029: OCM1 CTCF ChIP-seq  rep1; Homo sapiens; ChIP-Seq
library_construction_protocol: Whole cell extracts were sonicated to solubilize the chromatin. The chromatin extracts containing DNA fragments with an average size of 500 bp were immunoprecipitated using different antibodies.Purified immunoprecipitated DNA were prepared for sequencing according to a modified version of the Solexa Genomic DNA protocol. Fragmented DNA was end repaired and subjected to 18 cycles of LM-PCR using oligos provided by Illumina. Amplified fragments between 150 and 300bp (representing shear fragments between 50 and 200nt in length and ~100bp of primer sequence) were isolated by agarose gel electrophoresis and purified. Libraries were prepared according to Illumina's instructions accompanying the DNA Sample Kit (Part# 0801-0303). 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 15 cycles and library fragments of ~250 bp (insert plus adaptor and PCR primer sequences) were band isolated from an agarose gel. The purified DNA was captured on an Illumina flow cell for cluster generation. Libraries were sequenced on the Illumina HiSeq 2500 following the manufacturer's protocols.
attributes.tag: GEO Accession
attributes.value: GSM4678029