title: GSM4801430: HeLa DRIPc WT LS61H rep3; Homo sapiens; OTHER
library_construction_protocol: Standard illumina protocol. DRIP-seq and DRIPc-seq were performed as described in Sanz et al, 2016. Briefly, for DRIP-seq, genomic DNA was extracted from HeLa and K562 cell lines and fragmented using HindIII, EcoRI, BsrGI, XbaI and SspI. Monoclonal S9.6 antibody was used to enrich for RNA/DNA hybrid and RNA was removed using RNase H before being subjected to standard Illumina library construction protocol. For DRIPc-seq, enriched R-loop fragments were further subjected to DNase I treatment and the remaining RNA was subjected to second strand synthesis using dUTP instead of dTTP for strand-specific library construction. Illumina TruSeq Single adapter was ligated and the cDNA and amplified as per standard Illumina TruSeq Single end protocol.