title: GSM2641017: H209_H3K27me3_ChIPSeq; Homo sapiens; ChIP-Seq
library_construction_protocol: Cells were cross-linked with 1% formaldehyde for 10 min at room temperature and were prepared for ChIP. Briefly, cells were crosslinked with 1% formalin for 10 min, and crosslinked cell lysates underwent fragmentation by sonication and incubated with antibodies bound to protein A-sepharose beads (50% slurry) overnight at 4 ºC. The beads were washed several times and eluted with elution buffer (1% SDS, 0.1 M NaHCO3). The eluates were treated with 1.5 μg of pronase 2 hr at 42 ºC then incubated at 65 ºC over night to reverse the crosslinks. The ChIP’ed DNA was purified by phenol/chroloform treatment and precipitated with LiCl and 70% ethanol. Sample preparation for ChIP-seq was performed according to the manufacturer's instructions (Illumina). Briefly, size fractionated DNA was extracted and a single adenosine was added using Klenow exo– (3' and 5' exo minus; Illumina). Illumina adaptors were then added and DNA was subjected to 20 cycles of PCR according to manufacturer's instructions.
attributes.tag: GEO Accession
attributes.value: GSM2641017