title: GSM6585593: GöPDX4_leChRO; Homo sapiens; OTHER
library_construction_protocol: leChRO-seq was performed as previously described (DOI: 10.1038/s41588-018-0244-3). Extracted chromatin from cultured cells or homogenized PDX tissue samples was subjected to sonication. Chromatin run-on reaction was performed with biotin-11-UTP (Perkin Elmer) containing master mix at 37⁰C for 5 min.  After subsequent RNA isolation, biotin RNA enrichment was performed using the streptavidin magnetic beads (NEB). RNA was ligated with 3' RNA Adaptor using the T4 RNA ligase I (NEB).  After 2nd biotin enrichment, RNA was de-capped using RppH (NEB) and 5'-repaied using PNK (NEB) enzymes. After 5' RNA adaptor ligation, another round of biotin enrichment and RNA isolation was performed.Extracted RNA was reverse transcribed using SuperScript III RT enzyme (Invitrogen). The resultant DNA was PCR amplified using Phusion DNA Polymerase (NEB) with corresponding indexing primers.