Which statement describes the in vivo method of monoclonal antibody production?

• A. Using mice to grow hybridoma cells on their peritoneal lining.
• B. Using transgenic plants to express antibodies.
• C. Using cultured cells in vitro.
• D. Using bacterial fermentation.

Answer: (A)

The method relies on a living animal host to produce the antibodies. In this approach, hybridoma cells are introduced into the mouse’s peritoneal cavity. There, the cells proliferate and continuously secrete monoclonal antibodies into the ascitic fluid, which can then be collected in high yield. This is the classic in vivo way to produce monoclonal antibodies, using a mouse as the industry-compatible production system.

Other options describe systems that produce antibodies outside the living animal: plants as expression hosts, cultured cells in vitro, or bacterial fermentation. While these can produce antibodies, they do so outside the in vivo context of a mammalian host, which is what the statement in question is identifying.