title: ATAC-seq of IPSC-dervied human DS astrocytes
design: Fresh cell pellets from 50,000 cells were exposed to a hypotonic cell lysis buffer (0.1% (wt/vol) sodium citrate tribasic dihydrate and 0.1% (v/v) Triton X-100) for 30 minutes at 4 C followed by treatment with normal cell lysis buffer (10 mM Tris-HCl, pH 7.4, 10 mM NaCl, 3 mM MgCl2 and 0.1% (v/v) IGEPAL CA-630) for 30 minutes at 4 C. To perform the transposition reaction, the nuclei were incubated with 25 l of Transposase Master Mix (2.5 l 10~ TD buffer, 10 l H2O and 12.5 l Tn5 enzyme from an Illumina Nextera kit; FC-1211031) for 30 minutes at 37C. DNA was then purified and enriched by PCR using Nextera indexed primers, and the library was recovered with GeneRead Purification columns (Qiagen), eluted in 35ul EB buffer. The library was assessed using a bioanalyzer (Agilent) and sequenced on an Illumina HiSeq4000 instrument to produce 100bp paired-end reads.