Figure 4. Targeted chromosomal mutagenesis by PPG substituted G-rich TFOs. (A) Schematic describing gene-targeted mutagenesis assay. AV16 cells were transfected with TFOs using cationic lipids. Cells were collected for DNA isolation 48h post transfection to allot time for induction of mutations, before analysis of genomic DNA. (B) Dose dependence of PPG-substituted TFOs on targeted mutagenesis of the chromosomal supFG1 gene in AV16 cells. (C) The frequency of mutations in the supFG1 gene induced by AG30 or the PPG-substituted TFOs was calculated by dividing the number of colorless mutant plaques by the total number of plaques counted. Each experiment was performed three times and the standard errors were calculated for the mutation frequency values, as indicated by the error bars. *** P < 0.001 (D) Sequence analysis of the supFG1 gene mutations induced by the treatment of AV16 cells with PPG-TFOs, A6G30 and A8G30.