Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Cross-reactivity occurs when an antibody directed against one specific antigen also reacts with a different, but structurally similar, antigen. This phenomenon can have significant implications in diagnostic tests and immune responses.
5 Must Know Facts For Your Next Test
Cross-reactivity can lead to false positives in immunoassays like ELISA.
It is a major consideration in the design and interpretation of serological tests.
Autoimmune disorders can be exacerbated by cross-reactivity when the immune system attacks self-antigens that resemble foreign antigens.
In polyclonal antibody production, cross-reactivity is more common due to the variety of antibodies produced.
Monoclonal antibodies are less likely to exhibit cross-reactivity because they target a single epitope.