Fig 3.

Replication kinetics of parental biological APMV-7, wt rAMPV-7, and the indicated recombinant mutant viruses in embryonated chicken eggs (A) and in Vero (B) and DF-1 (C) cells. (A) Nine-day-old SPF embryonated chicken eggs were inoculated with 10³ TCID₅₀ of the indicated viruses. Allantoic fluids were harvested daily for virus titration. (B and C) Vero (B) and DF-1 (C) cells were infected in duplicate with the indicated viruses at an MOI of 1, and samples were collected from the culture supernatant at 24-h intervals until 120 h postinfection. Virus titers of the samples were determined by serial endpoint dilution, with infected wells detected by immunoperoxidase staining using anti-APMV-7 N protein rabbit serum.