title: GSM9663020: HepG2.2.15 cells, IgG(Chip); Homo sapiens; ChIP-Seq
library_construction_protocol: ChIP-seq was performed using the BeyoChIP Enzymatic ChIP Kit (Beyotime, P2083S) with minor modifications. Briefly, cells were cross-linked with 1% formaldehyde for 10 min at 37°C and quenched with 0.125M of glycine. Nuclei were isolated using Buffer A and Buffer B, followed by Micrococcal Nuclease (MNase) digestion. After adding ChIP Buffer, soluble chromatin was collected by centrifugation. An aliquot (2%) was saved as input, and the remainder was pre-cleared with Protein A/G magnetic beads, then incubated overnight at 4°C with XRCC5/6 antibodies. The next day, fresh beads were added for 2 h at 4°C, washed sequentially with low salt, high salt, LiCl, and TE buffers. Immune complexes were eluted and reverse-crosslinked overnight at 65°C, followed by phenol-chloroform extraction and ethanol precipitation. Purified DNA was used for library preparation and sequenced by Seqhealth (Wuhan). The high-throughput DNA sequencing libraries were prepared by using VAHTS Universal DNA Library Prep Kit for Illumina V3（Catalog NO. ND607, Vazyme）. The library products corresponding to 200-500 bps were enriched, quantified and finally sequenced on DNBSEQ-T7 sequencer (MGI Tech Co., Ltd. China) with PE150 model.