Kinetics of virus growth (A) and plaque development (B) of class 2 (open circles) and class 9 (closed circles) ILTV in LMH cells.

<p>(A) LMH cells were inoculated at multiplicity of infection of 0.001 and inocula removed at one hour post-inoculation. Triplicate wells were harvested at 24 hour intervals after infection and virus genome concentrations in the cell-free supernatant determined using qPCR. Error bars indicate standard deviations and asterisks indicate time points at which the mean concentrations of the two viruses were significantly different (P<0.05; Student’s t-test). (B) LMH cells were inoculated with virus, after which they were overlaid with methyl cellulose medium and incubated at 37°C. Nineteen to 26 individual plaques were photographed at each time point, and plaque area measured using Image J, calibrated using a stage micrometer. Plaques induced by each of the viruses differed significantly in mean area at each time point (P < 0.004; Student’s t-test).