title: GSM5455109: ATAC.Day28; Mus musculus; ATAC-seq
library_construction_protocol: 50000-100000 cells were pelleted by centrifugation and re-suspended in 100 µl of cold lysis buffer (10mM Tris-HCl pH 7.4, 10mM NaCl, 3mM MgCl2, 0.1% NP40, 0.1% Tween-20 and 0.01% Digitonin). After incubation on ice for five minutes, lysis was washed out by adding 1 mL of lysis buffer without NP40 and digitonin. Nuclei were pelleted by centrifugation for 10 min at 500g, 4 ºC.  The supernatant was discarded and nuclei were re-suspended in 50 µl of reaction buffer containing 1.5 µl of Tn5 transposase (Illumina), 10 ul of 5x transposase buffer (50mM Tris-HCl, pH 8.4 and 25mM MgCl2), 16.5 µl PBS, 0.5 µl of 1% digitonin, 0.5 µl of 10% Tween-20. The reaction was incubated at 37ºC for 30 minutes with 600 RPM mixing and cleaned up with PCR purification kit. The eluted DNA were then used for library preparation and sequenced on an Illumina Hiseq4000/HiseqX platform.