title: GSM1467464: H3K4me2 ckit.neg; Mus musculus; ChIP-Seq
library_construction_protocol: 0.7% Fixed leukemia cells were lysed for 20 min in nuclear lysis buffer (50 mM Tris-HCl pH 8.0, 10 mM EDTA, 1% SDS) containing freshly added 1x proteinase inhibitor cocktail (Roche) on ice, then sonicated to generate DNA fragments of 150-500 base pair using a Diagenode Bioruptor XL sonicator for a total duration of 60 cycles (30 seconds ON and 30 seconds OFF). The soluble chromatin was diluted 10-fold with ChIP dilution buffer (20m M Tris-HCl pH 8.0, 150 mM NaCl, 2 mM EDTA, 0.01% SDS, 1% Triton-x 100) containing 1x proteinase inhibitor cocktail, and the diluted duration of 60 cycles (30 seconds ON and 30 seconds OFF). The soluble chromatin was diluted 10-fold with ChIP dilution buffer (20m M Tris-HCl pH 8.0, 150 chromatin (1 mL equivalent to 2 million cells) was subjected to immunoprecipitation using various ChIP grade antibodies coupled with protein A magnetic beads (Invitrogen). DNA was used for ChIP-seq library construction based on manufacturer's protocol with modifications to account for limited number of cells (Schmidt et al., 2009).