IP-1
For each sample, At least 5 ng ChIP product was used for library preparation using VAHTS Universal Pro DNA Library Prep Kit (Vazyme, #ND-608). The ChIP product was treated with End Prep Enzyme Mix for end repairing, 5 Phosphorylation, and dA-tailing in one reaction, followed by ligation to adaptors with a T base overhang. Adaptor-ligated DNA was recovered using AxyPrep Mag PCR Clean-up (Axygen, #MAG-PCR-CL-50) and amplified by PCR for 10 cycles using P5 and P7 primers, with both primers carrying sequences which can anneal with flowcell to perform bridge PCR and P7 primer carrying a six-base index allowing for multiplexing. PCR products were cleaned using AxyPrep Mag PCR Clean-up, validated using an Agilent 2100 Bioanalyzer, and quantified by Qubit 2.0 Fluorometer. Then libraries with different indexes were multiplexed and loaded on an Illumina instrument (Illumina, USA). Sequencing was carried out using a 2x150 paired-end (PE) configuration; image analysis and base calling were conducted by the HiSeq Control Software (HCS) + OLB + GAPipeline-1.7 (Illumina) on the Illumina instrument by GENEWIZ (Suzhou, China).