Indirect immunofluorescence assay (IFA)

Definition

Indirect immunofluorescence assay (IFA) is a laboratory technique used to detect the presence of specific antibodies or antigens in a sample. It involves the use of fluorescent-labeled secondary antibodies that bind to primary antibodies attached to the target antigen.

5 Must Know Facts For Your Next Test

1. IFA uses a two-step process involving primary and secondary antibodies.
2. The secondary antibody in IFA is conjugated with a fluorescent dye.
3. It's commonly used in diagnosing autoimmune diseases and infectious diseases.
4. Fluorescence microscopy is employed to visualize the results of an IFA.
5. Proper controls are essential to validate the specificity and sensitivity of the assay.

Review Questions

• What role does the secondary antibody play in an indirect immunofluorescence assay?
• Why is fluorescence microscopy important in IFA?
• How does IFA differ from direct immunofluorescence?

Related terms

Direct Immunofluorescence Assay (DFA): A technique where fluorescently labeled primary antibodies directly bind to target antigens.

Fluorophore: A fluorescent chemical compound that can re-emit light upon light excitation.

Antigen:

A substance that induces an immune response, often by binding to specific antibodies.