MEF_Cre_postTAM_ATAC-seq_rep3
ATAC-seq was performed as described in (Buenrostro et al., 2013). Nuclei were isolated from 50,000 cells in cold lysis buffer (10 mM Tris-HCl pH 7.4, 10 mM NaCl, 3 mM MgCl2, 0.1% NP40, protease inhibitor cocktail). The isolated nuclei were mixed with Nextera (Illumina) TD buffer and Tn5 transposase and incubated at 37C for 30 min for transposition reaction. The transposed DNA was purified using MinElute PCR Purification Kit (Qiagen) and amplified by PCR with Nextera index primers. The initial 5 cycles of PCR were performed, and an aliquot of the initial reaction was subjected to qPCR to determine additional cycle number of the next PCR. ATAC-seq libraries were purified using MinElute PCR Purification Kit (Qiagen). The quantity and quality of libraries were respectively monitored by library quantification kit (Kapa Biosystems) and Bioanalyzer (Agilent) for 75bp, paired-end Illumina NextSeq.