Moloney-based retroviral vectors (pMXs) were co-transfected with packaging plasmids (pCMV-gag-pol-PA and pCMV-VSVg) in 293T cells using Lipofectamine 2000 (Invitrogen) according to manufacturer's instructions. Retroviral supernatants were collected 48 h after transfection, passed through a 0.45 μM filter to remove cellular debris and stored at 4 °C for up to 7 days. Lentiviral vectors were co-transfected with packaging plasmids (pMDL, Rev and VSVg) in 293T cells using Lipofectamine 2000 (Invitrogen) according to manufacturer's instructions. Lentiviral supernatants were collected 48 h after transfection, concentrated by ultracentrifugation at 19400, r.p.m. for 2 h, resuspended in PBS and stored at −80 °C.
