Lentiviruses were produced as described previously (Brennand et al., 2011, Ho et al., 2016). The lentiviral constructs expressing dCas9:VP64-T2A-Puro or dCas9:VPR-T2A-Puro or dCas9:KRAB-T2A-Puro (EF1α-dCas9:VP64-T2A-Puro or EF1α-dCas9:VPR-T2A-Puro or EF1α-dCas9:KRAB-T2A-Puro, respectively) are described above. Physical titration of lentivirus was performed by qPCR (qPCR Lentivirus Titration [Titer] Kit, ABMgood, no. LV900).
