Targeting of hESCs and hiPSCs using TALEN mediated homologous recombination hESCs and hiPSCs were cultured in Rho Kinase (ROCK)-inhibitor (Calbiochem;

Cell culture Cell culture techniques have been described previously. C1 hiPSCs and the hESC lines WIBR#3 were maintained on mitomycin C inactivated mouse embryonic fibroblast (MEF) feeder layers in hESC medium [DMEM/F12 (Invitrogen) supplemented with 15% fetal bovine serum (FBS) (Hyclone), 5% KnockOutTM Serum Replacement (Invitrogen), 1 mM glutamine (Invitrogen), 1% nonessential amino acids (Invitrogen), 0.1 mM β-mercaptoethanol (Sigma) and 4 ng/ml FGF2 (R&D systems)]. Cultures were passaged every 5 to 7 days either manually or enzymatically with collagenase type IV (Invitrogen; 1.5 mg/ml). In order to partially remove feeder cells prior to FACS analysis, OCT4-eGFP targeted hESCs were passaged using collagenase. Cells were plated onto matrigel coated plates and cultured for 24-48 hours in mTESRI medium prior FACS analysis.