Avidity

Definition

Avidity is the overall strength of binding between an antibody and its antigen. It reflects the combined stability of multiple antigen-antibody interactions.

5 Must Know Facts For Your Next Test

1. Avidity measures the cumulative binding strength between an antibody with multiple antigenic sites.
2. Higher avidity indicates stronger and more stable antibody-antigen interactions.
3. Avidity is distinct from affinity, which measures the strength of a single binding site interaction.
4. IgM antibodies generally have higher avidity due to their pentameric structure allowing multiple binding sites.
5. Avidity maturation occurs during an immune response, enhancing the effectiveness of antibodies.

Review Questions

• What does avidity measure in the context of antibodies?
• How does avidity differ from affinity?
• Why do IgM antibodies typically exhibit higher avidity compared to other antibody classes?

Related terms

Affinity: The strength of a single interaction between an antigen and an antibody's binding site.

Epitope: The specific part of an antigen that is recognized and bound by an antibody.

IgM: A class of antibodies known for their pentameric structure, contributing to high avidity.