GSM5117456: ATAC-Seq 1555; Homo sapiens; ATAC-seq
20,000 CD138+CD38+PI- viable myeloma cells were sorted into PBS and kept on ice. Cells were isolated by centrifugation at 500 g for 10 minutes at 4°C and the supernatant was carefully removed by pipet.   Cells were resuspended in 50 uL of nuclei-lysis buffer (10 mM Tris pH 7.4, 10 mM NaCl, 3mM MgCl2, 0.1% IGEPAL) prior to centrifugation at 500 g for 30 minutes at 4°C and careful removal of nuclei-lysis buffer by pipet. Nuclei were resuspended in 25 uL of tagmentation mix consisting of 10.5 uL H2O, 12.5 uL TD Buffer (Illumina) and 2 uL Tn5 transposase (Illumina) and incubated at 37 °C for 1 hour. After tagmentation, DNA was isolated by digesting with 20 mg Proteinase K for 1 hour in 25 uL of tagmentation clean-up buffer (326 mM NaCl, 109 mM EDTA, 0.63% SDS). High molecular weight DNA was excluded by 0.6 x volume negative selection with SPRI beads (Kapa Biosystems) followed by a 1.2 x SPRI bead positive selection, which was repeated twice. ATAC libraries were amplified for 12 PCR cycles using Nextera adapters (Illumina) prior to sequencing on an Illumina HiSeq 4000.