Multicycle replication of reassortant viruses in MDCK and QT-35 cells. MDCK and QT-35 cell monolayers were inoculated with each virus at an MOI of 0.00001. After the inoculum had adsorbed for 1 h, the cell monolayers were washed three times with PBS, and infection medium was added. Culture supernatants were collected at the indicated time points and titrated on MDCK cells. (A) MDCK cells; (B) QT-35 cells. *, P < 0.05 based on one-way ANOVA. The Bonferroni adjusted probabilities were 0.002 for rH5N3 versus rH7N3 at 72 h postinoculation in MDCK cells and 0.006 for rH5N3 versus rH5N1 at 96 h postinoculation in MDCK cells. The Bonferroni adjusted probabilities were 0.004 for rH5N3 versus rH5N1 at 72 h postinoculation in QT-35 cells, 0.005 for rH5N3 versus rH7N3 at 72 h postinoculation in QT-35 cells, and 0.003 for rH5N1 versus rH7N3 at 96 h postinoculation in QT-35 cells.