How are monoclonal antibodies produced?

• A. By mixing different types of B cells
• B. From a single clone of B cells
• C. By natural selection in a laboratory
• D. Through the activation of T cells

Answer: (B)

Monoclonal antibodies are produced from a single clone of B cells. The process typically begins by immunizing a host animal, such as a mouse, with a specific antigen. This stimulates B cells in the animal's immune system to produce antibodies against that antigen. The next step is to harvest these B cells and fuse them with myeloma cells (cancerous B cells) to create hybridoma cells. These hybridomas possess the ability to proliferate indefinitely and produce the desired antibody specific to the antigen.

Since all the hybridoma cells are derived from a single B cell that was activated by the antigen, the resulting antibodies are identical and specific to that one antigen, hence termed "monoclonal." This allows for a consistent and reproducible product that can be used in various therapeutic and diagnostic applications. The other choices do not accurately represent the specific process of monoclonal antibody production, as mixing different B cells would yield polyclonal antibodies, natural selection does not apply in this context, and T cell activation is not involved in the generation of B cells that produce antibodies.