Which of the following is not a method of culturing animal viruses?

• A. Laboratory animal inoculation
• B. Cell culture
• C. Agar plate inoculation
• D. Embryonated egg inoculation

Answer: (A)

Growing animal viruses requires a living host or tissue that the virus can infect and use to replicate. In vivo approaches use laboratory animals, providing a whole-organism environment for viral propagation. In vitro cell culture offers isolated host cells in a controlled setting where viruses can invade and reproduce. Embryonated eggs provide a developing tissue rich in susceptible cells, widely used for vaccine production. Plating onto an agar surface by itself does not supply a living host for viral replication; while an agar overlay is used in plaque assays to quantify virus after it has infected a cell monolayer, it is not a method to culture and expand the virus. Thus, agar plate inoculation is not a method for culturing animal viruses.