title: GSM4728108: GTFR230_Input; Homo sapiens; ChIP-Seq
library_construction_protocol: Four 15-cm dishes of confluent cells were fixed in formaldehyde for 10 min, before quenching the fixation with glycine. Cells were collected, lysed in a sarkosyl-containing lysis buffer and sonicated  to yield 100- to 300-bp genomic DNA fragments. Five micrograms of an antibody raised against H3K27ac was incubated with blocked magnetic Dynabeads (Life Technologies) at 4 °C for 4 h. Antibody–bead conjugates were incubated with 100 μg of chromatin at 4 °C overnight, with constant agitation. Beads were washed extensively with RIPA buffer and then treated with RNase and proteinase K (both Qiagen). DNA was then eluted from the beads in TE buffer and cleaned up using the QIAquick PCR Purification kit (Qiagen).  ChIP libraries were constructed using the Kapa Hyper Library Preparation kit, according to the manufacturer's instructions. Library construction was carried out according to the manufacturer's instructions using Bio NextFLex adaptors diluted 1:50. Final PCR on a portion of the adaptor ligation was performed for 12 cycles. Products were evaluated on an Agilent Bioanalyzer, using high-sensitivity DNA chips. ChIP libraries were quantified using the Kapa Biosystems Illumina library quantification kit, before pooling for sequencing.