Inducible Knockout of Chromatin Remodelers in Mouse ES Cells

Mouse ES cells were cultured using standard conditions. ES culture media containing Dulbecco’s Modified Eagle’s Medium (Cat# 10829018; Life Technologies), 15% FBS (Cat# ASM-5007; Applied StemCell), Penicillin-Streptomycin (Cat# 15140122; Life Technologies), Glutamax (Cat# 35050061; Life Technologies), HEPES buffer (Cat# 15630080; Life Technologies), 2-mercaptoethanol (Cat# 21985023; Life Technologies), MEM-NEA (Cat# 11140050; Life Technologies), and LIF supplement^{40 (link)}, was replaced daily, and ES cells were passaged every 48 hours. For inducible deletions, Smarca4^flox/flox actin–CreER ES cells^{4 (link)} or Arid1a^flox/flox actin–CreER ES cells, which previously tested negative for mycoplasma contamination using PCR testing, were respectively plated onto irradiated feeder mouse embryonic fibroblasts, treated with 0.8 uM 4-hydroxytamoxifen (Tam) or ethanol (EtOH) for 48 h, and harvested for further experiments after trypsin dissociation at 72 h. A549 cells were obtained from ATCC (Cat# CCL-185), and directly cultured upon receipt without testing for mycoplasma contamination, using F-12K media supplemented with 10% FBS and Penicillin-Streptomycin.