Human pluripotent stem cells repair mismatches more efficiently than parental fibroblasts. Repair of a transfected heteroduplex plasmid encoding GFP with a premature stop codon and red fluorescent protein (RFP) as a transfection control was measured in HeLa, H1, CT-2, YK26, Rx13, and HDFa cells. A, representative flow cytometry images. B, quantitation of repair rates in transfected cells. * represents p < 0.01. C, Western blot analysis confirming the knockdown of MSH2 or MLH1 in YK26. Actin is included as a loading control. D, the percentage of heteroduplex repair in control and MSH2 or MLH1 knockdown (KD) YK26 cells. The values represent the means of three independent experiments. * represents p < 0.01. Error bars represent S.E.