Monoclonal antibodies are produced by

• A. Cultured T cells
• B. Human plasma cells
• C. Mouse plasma cells
• D. Hybridomas

Answer: (D)

Monoclonal antibodies are produced by hybridomas. This technique creates an immortal cell line that both secretes a single type of antibody and divides indefinitely. A B cell that makes the desired antibody is fused with a myeloma (cancer) cell, yielding a hybridoma that inherits the antibody’s specificity from the B cell and the endless growth of the myeloma. That combination is why the antibodies produced are uniform and available in large quantities. Mature T cells don’t make antibodies, and plasma cells (from mice or humans) alone produce antibodies but are not inherently immortal, so they can’t sustain long-term production without fusion to a myeloma line.