Fig. 2

Production of antibodies. (a) Serum was collected from the ducks at 3, 10, 17, 24, 31, 38, 48 and 60 dpi. Gradient dilutions of serum and viral fluids were mixed and incubated with DEF cells for 1 h, then the mixture was removed, and DMEM with 2% serum was added. The DEF cells were cultured at 37 °C and observed for 5 days to record the lesions of cells. (b) The IgG antibodies in sera specific to the TMUV E protein were checked by ELISA. The serum samples collected from ducks were diluted and incubated with an E protein-coated plate. The specific anti-TMUV-E protein antibodies were measured by horseradish peroxidase-conjugated goat anti-duck IgG. The values of IgG are shown as the means ± standard deviations (n = 3 for each time point). The dashed line shows the detection limit for a positive response