Cell were fixed with 1.6% paraformaldehyde for 20 minutes. After quenching, TSA-reaction (proximity-labelling) and cell lysis, genomic DNA was sonicated using Covaris S220 sonicator. TSA-Seq libraries were constructed using TruSeq Nano DNA High Throughput Library Prep Kit. 0.1 ug of genomic DNA was sheared using adaptive focused acoustic technology (Covaris) and the fragmented DNA is end-repaired to create 5'-phosphorylated, blunt-ended dsDNA molecules. Following end-repair, DNA was size selected with bead-based method. These DNA fragments go through the addition of a single 'A' base, and ligation of the TruSeq DNA UD Indexing adapters. The products are then purified and enriched with PCR to create the final DNA library.