Question

For many uses in the laboratory, polyclonal antibodies work well, but for some types of assays, they lack sufficient ________ because they cross-react with inappropriate antigens.

a) Specificity
b) Sensitivity
c) Reactivity
d) Affinity

Answer 1

Polyclonal antibodies can lack specificity in certain laboratory assays due to cross-reactivity with multiple antigens, while monoclonal antibodies offer high specificity by targeting a single epitope.

Step-by-step explanation:

For many laboratory assays, polyclonal antibodies are effective, but their tendency to cross-react with a variety of antigens can be a problem. This cross-reactivity highlights the lack of specificity, which is crucial for certain types of assays that require precise antigen recognition. Monoclonal antibodies, in contrast, provide high specificity by binding to a single epitope, thereby reducing the potential for cross-reactivity.

An antibody's specificity stems from the unique patterns of amino acids in the variable regions of the antibody that form antigen-binding sites designed to attach to complementary molecular sequences on the target antigens. Specificity is therefore a critical characteristic in distinguishing between different but chemically similar antigens to prevent false-positive or false-negative results in diagnostic tests.