Figure 4

Polymerase activity of H3N2 vRNPs substituted with 2009 pdmH1N1 PB1, PB2, PA and NP. Recombinant vRNPs were transfected into (a) 293T and (b) A549 cells at an incubation temperature of 37°C. Polymerase activity as reflected by the normalized relative light units was expressed as relative activity (mean ± standard deviation, n = 3) compared to the parent H3N2 vRNP, * represents statistical significance at p < 0.05.