Cross-reactivity

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

1. Cross-reactivity can lead to false positives in immunoassays like ELISA.
2. It is a major consideration in the design and interpretation of serological tests.
3. Autoimmune disorders can be exacerbated by cross-reactivity when the immune system attacks self-antigens that resemble foreign antigens.
4. In polyclonal antibody production, cross-reactivity is more common due to the variety of antibodies produced.
5. Monoclonal antibodies are less likely to exhibit cross-reactivity because they target a single epitope.

Review Questions

• How does cross-reactivity affect the accuracy of ELISA tests?
• Why is cross-reactivity a concern in autoimmune disorders?
• What is the difference between polyclonal and monoclonal antibodies in terms of cross-reactivity?

Related terms

Antigen-Antibody Complex:

The binding of an antibody to its specific antigen.

Monoclonal Antibody: An antibody produced by a single clone of cells, targeting one specific epitope.

Polyclonal Antibody: A mixture of antibodies produced by different B cell clones, each recognizing different epitopes on the same antigen.