Affinity

Definition

Affinity refers to the strength of the interaction between an antibody and its specific antigen. It is a measure of how tightly an antibody binds to its antigenic target.

5 Must Know Facts For Your Next Test

1. Affinity is determined by the fit between the antigen-binding site of an antibody and its specific epitope on the antigen.
2. High-affinity antibodies bind more tightly to antigens, leading to more effective immune responses.
3. Affinity maturation occurs in B cells through somatic hypermutation and selection for higher affinity antibodies.
4. Monoclonal antibodies are typically produced to have high affinity for a single epitope, making them useful in diagnostics and therapeutics.
5. The concept of affinity is critical in understanding both polyclonal and monoclonal antibody production.

Review Questions

• What is meant by 'affinity' in the context of antibody-antigen interactions?
• How does affinity maturation contribute to the effectiveness of an immune response?
• Why are high-affinity monoclonal antibodies important in therapeutic applications?

Related terms

Epitope:

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

Somatic Hypermutation:

A process that occurs in B cells resulting in mutations that increase antibody affinity.

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