FIG. 3.

(A) Plaque morphology of YF17D, MOD, and the MOD/YF17D chimeric virus on Vero cells 4 days after infection; (B) growth kinetics of MOD (▴), YF17D (□) and MOD/YF17D (•) in Vero cells. Quantification of viral RNA in the supernatant was performed (in triplicate) by real-time quantitative RT-PCR (the standard deviation of triplicate determinations was <15% [not shown]). Comparable data were obtained in an independent experiment. (PCRU, PCR-units [one PCR-unit is defined as the lowest template copy number detectable in three of three replicative reactions as determined by limiting dilution series.)