ATAC-Seq of homo sapiens: pancreatic islets
frozen nuclear pellets of 5 x 104 cells were thawed on ice, re-suspended in 50l of transposition reaction mix (2.5l of Tn5 transposase in 1x TD buffer (Illumina)) for 30min at 37C in a thermomixer with gentle shaking. Immediately following transposition, tagmented DNA was purified using a MinElute Kit (Qiagen) or a DNA Clean & Concentrator-5 kit (Zymo) and eluted in 10l of nuclease-free H2O. 5l of the purified sample was PCR amplified for 12 cycles using KAPA Real-Time Library amplification kit (KAPA Biosystems) and customized Nextera PCR primers (as in Buenrostro et al., 2013). Amplified libraries were purified using AMPure XP (Beckman Coulter) beads and eluted in 12-15l of nuclease-free H2O. Libraries were sequenced on an Illumina HiSeq2500