title: GSM1876372: Helios_ChIP_CD4+_Treg; Mus musculus; ChIP-Seq
library_construction_protocol: In vitro activated CD4+ and CD8+ Tregs were fixed with 1% formaldehyde and flash frozen at -80°C.  The fixed cells were lysed and the chromatin was sheared using a Covaris E210 Ultrasonicator.  Transcription factor-DNA and histone-DNA complexes were immunoprecipitated and then eluted from magnetic beads.  The formaldehyde crosslinks were reversed, and the ChIP DNA fragments were purified. ChIP DNA was prepared for high-throughput Illumina sequencing using the NEBNext ChIP-Seq Library Master Mix Set for Illumina kit and the NEBNext Multiplex Oligos for Illumina kit according to a modified manufacturer's protocol.  For each ChIP or input sample, 50 ng of DNA was used to prepare a sequencing library.  The DNA fragments were end-repaired, dA-tailed, and ligated to illumina adaptors according th the kit instructions.  DNA fragments of 150-600 bp in length were then selected using Pippin Prep 2% Agarose Gel Cassettes and the Pippin Prep DNA Size Selection System.  The ChIP DNA was then amplified with 12 PCR cycles using the NEBNext Multiplex Oligos.  Amplifed DNA was purfied using a 1:1 ratio of DNA to Agencort AMPure XP beads.
attributes.tag: GEO Accession
attributes.value: GSM1876372