What is the difference between a monoclonal antibody and a polyclonal antibody?

What is the difference between a monoclonal antibody and a polyclonal antibody?

• A. The polyclonal antibody is made from T-cells.
• B. The polyclonal antibody has a longer life span.
• C. The monoclonal antibody reacts to only one antigen.
• D. The monoclonal antibody reacts with only one site on an antigen.

Answer: (D)

Monoclonal antibodies come from a single B-cell clone, so they bind to a single epitope—one specific small site—on an antigen. Polyclonal antibodies are a mixture produced by many B-cell clones, each recognizing different epitopes on the same antigen, so they can bind multiple sites. That makes the statement about the monoclonal antibody reacting with only one site on an antigen the most precise description. Antibody production is by B cells, not T cells, so saying polyclonal antibodies come from T cells isn’t correct. Lifespan differences aren’t the defining feature here, and describing monoclonal binding as to only one antigen is less precise than noting it targets a single epitope.

Monoclonal antibodies come from a single B-cell clone, so they bind to a single epitope—one specific small site—on an antigen. Polyclonal antibodies are a mixture produced by many B-cell clones, each recognizing different epitopes on the same antigen, so they can bind multiple sites. That makes the statement about the monoclonal antibody reacting with only one site on an antigen the most precise description. Antibody production is by B cells, not T cells, so saying polyclonal antibodies come from T cells isn’t correct. Lifespan differences aren’t the defining feature here, and describing monoclonal binding as to only one antigen is less precise than noting it targets a single epitope.