title: GSM5265324: SJALL068666 cells - BCL11B; Homo sapiens; ChIP-Seq
library_construction_protocol: Thawed cryopreserved leukemia cells were washed once in PBS and resuspended in PBS at a concentration of 1 million cells/ml. 37% formaldehyde was added to a final concentration of 1% and cells were crosslinked for 10 minutes at room temperature. Crosslinking was quenched with the addition of glycine at a final concentration of 0.1M and incubated at room temperature for 5 minutes. Cells were spun at 4˚C, washed once more with ice-cold PBS and flash frozen in aliquots of 4 million cells. For each immunoprecipitation, one aliquot of 4 million crosslinked cells was used. Cells were sheared in Covaris microTUBEs (Covaris 520045) at the equivalent of 2 million cells per tube using a Covaris E220 instrument with the following settings: peak power = 140 watts, duty factor = 5, cycles/burst = 200, time = 9 minutes, temperature = 4˚C. The following antibodies were used: 1 ug of H3K27ac (Active Motif am91193) or a cocktail of 4 antibodies for BCL11B, 0.5 ug each (Cell Signaling Technologies 12120, Abcam ab18465, Bethyl Laboratories A300-383A and A300-385A). Immunoprecipitated DNA was prepared for Illumina sequencing using the Kapa Hyper Prep Kit (Kapa KR0961) and 11 (H3K27ac) or 19 (BCL11B) PCR cycles.  Libraries were sequenced in paired-end mode to an average depth of 387 million reads.