Instrument: Illumina HiSeq 1500
Strategy: DNase-Hypersensitivity
Source: GENOMIC
Selection: DNase
Layout: SINGLE
Construction protocol: Nuclei were isolated from cells grown on 150 mm dishes using a 0.04% NP-40 buffer (15 mM Tris-HCl pH=8.0, 15 mM NaCl, 60 mM KCl, 1 mM EDTA pH=8.0, 0.5 mM EGTA pH=8.0, 0.5 mM Spermidine). 10 million freshly isolated nuclei were treated with 40 units/ml DNase I for 3 minutes at 37°C as decribed previously (Siersbaek R, et al.2011. EMBO Journal 30:1459-72). After RNase and Proteinase K treatment, DNA was isolated by phenol-chloroform-extraction and separated by ultra-centrifugation on a sucrose gradient overnight. DNA-fragments between 100 and 500 bp (representing 2-hit cutting events) were isolated, checked for enrichment of open chromatin over background using real- time PCR. DNase-seq and ChIP-seq libraries were constructed from 10 to 20 ng of genomic DNA according to the manufacturer's instructions (Illumina) as described in (Nielsen R, et al. 2014. Methods in Enzymology 537: 261-279).