title: GSM6514276: H9 Passage 4 CNCC, Input, for tracks [ChIP]; Homo sapiens; ChIP-Seq
library_construction_protocol: ChIP experiments were performed as described in (Long et al. 2020) [PMID: 32991838]. For each biological replicate, 10 million single-cell CNCCs or post-ECM-digested chondrocytes were fixed in suspension in 1% methanol-free formaldehyde diluted in serum-free medium with end-over-end rotation, quenched with 0.125M Glycine (final concentration), washed twice with ice-cold PBS, pelleted by centrifugation, and snap-frozen in liquid nitrogen. 1mL of lysed cells was sonicated on a Bioruptor sonicator 4 times (8-cycles; power, high; "on" interval, 30 sec; "off" interval, 45 seconds; temperature 4°C). Libraries were constructed using protocol recommended by NEBNext Ultra II DNA Library Prep Kit for Illumina (Cat No. E7645) with unique dual indexes. We used adaptors consisting of unique i5 and i7 barcodes and unique molecular identifiers (IDT xGen UDI-UMI Adapters Cat No 10005925)