title: GSM6423189: DIPGXIII K27M H33ChIP L14; Homo sapiens; ChIP-Seq
library_construction_protocol: 5 million cells were fixed in growth media with 0.4% formaldehyde for 10 min and quenched with 125 mM glycine. Chromatin was released by sequential lysis with cells lysis buffer (10 mM Tris pH 8, 10 mM NaCl, 0.2% Igepal) and nuclear lysis buffer (50 mM Tris pH 8, 10 mM EDTA, 1% SDS). Chromatin was sheared to ≈300 bp with 12 rounds of sonication (30 s on, 30 s off) on a Bioruptor (Diagenode) and incubated overnight at 4 ᵒC with 5 μg H3.3 antibody (Abcam, Ab176840). Samples were immunoprecipitated with Protein A Agarose beads (Sigma-Aldrich, 05015979001) and washed sequentially with low salt (20 mM Tris pH 8, 2 mM EDTA, 50 mM NaCl, 1% Triton X-100, 0.1% SDS), high salt (20 mM Tris pH 8, 2 mM EDTA, 500 mM NaCl, 1% Triton X-100, 0.01% SDS), and LiCl buffers (10 mM Tris pH 8, 1 mM EDTA, 0.25 M LiCl, 1% Igepal, 1% sodium deoxycholate). Chromatin was eluted with elution buffer (1% SDS, 100 mM NaHCO3), decrosslinked overnight at 65ᵒC, incubated with Proteinase K, phenol chloroform extracted and ethanol precipitated. Ovation Ultralow System V2 using Nugen protocols M01379 v3.1. Denaturing and on-board clustering using 2pM of library pool containing 1% PhiX, Illumina protocol 15048776 v15 Apr 2020. 75 SR sequencing using Illumina NextSeq550 High output mode and v2.5 chemistry. Illumina Protocol 15069765 v06, Jul 2019.