Dataset features

Specifications


Application: ChIP-seq analysis
Number of samples: 171
Release date: Jun 7 2012
Last update date: Jan 23 2018
Access: Public
Computational protocol: Bowtie, MEME Suite, TRANSFAC
Dataset link Histone Modifications by ChIP-seq from ENCODE/University of Washington

Experimental Protocol


Cells were grown according to the approved ENCODE cell culture protocols (http://hgwdev.cse.ucsc.edu/ENCODE/protocols/cell). Cells were cross-linked with 1% formaldehyde, and the reaction was quenched by the addition of glycine. Fixed cells were rinsed with PBS, lysed in nuclei lysis buffer, and the chromatin was sheared to 200-500 bp fragments using a Fisher Dismembrator (model 500). Sheared chromatin fragments were immunoprecipitated with specific polyclonal antibodies at 4 °C with gentle rotation. Antibody-chromatin complexes were washed and eluted. The cross-linking in the immunoprecipitated DNA was reversed and treated with RNase-A. Following proteinase K treatment, the DNA fragments were purified by phenol-chloroform-isoamyl alcohol extraction and ethanol precipitation. A quantity of 20-50 ng of ChIP DNA was end-repaired, followed by the addition of adenine, ligation to Illumina adapters, and creation of a Solexa library for sequencing. ChIP-seq affinity was directly measured through the raw tag density (Raw Signal), which is shown in the track as density of tags mapping within a 150 bp sliding window (at a 20 bp step across the genome). ChIP-seq affinity zones (HotSpots) were identified using the HotSpot algorithm described in Sabo et al. (2004). One percent false discovery rate thresholds (FDR 1.0%) were computed for each cell type by applying the HotSpot algorithm to an equivalent number of random uniquely mapping 36-mers. ChIP-Seq affinities (Peaks) were identified as signal peaks within FDR 1.0% hypersensitive zones using a peak-finding algorithm. All tracks have a False Discovery Rate of 1% (FDR 1.0%). Data were verified by sequencing biological replicates displaying a correlation coefficient > 0.9.

Repositories


GEO

GSE35583

ArrayExpress

E-GEOD-35583

ENA

SRP015928

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