🦠microbiology review

Indirect immunofluorescence assay (IFA)

Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025

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.
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