Identical antibodies produced from a single clone of plasma cells are described as which type of antibodies?

• A. Reagin
• B. Cold agglutinins
• C. Heterophile antibodies
• D. Monoclonal antibodies

Answer: (D)

Monoclonal antibodies are produced by a single clone of plasma cells, giving a population of identical antibodies that all recognize the same epitope. This uniformity comes from deriving all antibody molecules from one B cell clone, often via hybridoma technology, which is why they are described as identical and specific.

In contrast, the other terms refer to antibodies defined by function or reactivity rather than their clonality. Reagin antibodies are a broad, non-specific class used in certain serologic tests; cold agglutinins are antibodies (usually IgM) that bind red blood cells at cold temperatures; heterophile antibodies cross-react with antigens from different species. None of these imply a single clone producing identical molecules, which is the hallmark of monoclonal antibodies.