title: GSM8035938: APOE3/3 iMG LD Negative22 [ATAC-seq]; Homo sapiens; ATAC-seq
library_construction_protocol: Approximately 100,000 iMG were pelleted at 300 xg and 4 oC. Next, pellets were gently resuspended in ice-cold 50 μL lysis buffer (10 mM Tris-HCl pH 7.4, 10 mM NaCl, 3 mM MgCl2, 0.1% IGEPAL CA-630) and spun down at 500 xg for 10 min and 4 oC. The supernatants were discarded, and pellets gently resuspended in 50 μL of transposition reaction mix (25 μL tagment DNA buffer (Nextera, Illumina), 2.5 μL tagment DNA enzyme (Nextera, Illumina), 22.5 μL nuclease free water) and incubated at 37 oC for 30 minutes. Tagmented DNA was purified using MinElute PCR purification kit (Qiagen) and size selected for 70 – 500 bp using AmpureXP beads (Beckman Coulter). Libraries were constructed and amplified using 1.25 μM Nextera index primers and NEBNext High-Fidelity 2x PCR Master Mix (New England BioLabs). A quantitative PCR was run to determine the optimal number of cycles. Libraries were gel size selected for 165-300 bp fragments and single-end sequenced for 100 cycles (PE100) on an Illumina NovaSeq6000.