FIGURE 1.

Identification of siRNA concentrations that induce target silencing equal to that induced by corresponding lentiviral shRNA vectors. HeLa cells were either transfected with siRNA by use of RNAiMax at three different concentrations of oligonucleotide duplex or infected with lentiviral vectors encoding the same duplex as a hairpin in the context of the lentiviral vector pLenti6 (LV-shRNA). RNA was harvested 24 h after transfection or 36 h after infection and analyzed by quantitative real-time PCR for target gene silencing by use of gene specific probes from ABI. Error bars, SDs in technical replicates. Target silencing for siRNA transfections (blue bars) was compared with mock transfected cells, whereas silencing induced by LV-shRNA (red bars) was compared with samples infected with the control virus H1-TERM (no shRNA control vector). For gene expression profiling comparisons, siRNA concentrations that resulted in levels of target silencing similar to that induced by LV-shRNA infection were used.