Antinuclear Antibody by Immunofluorescence Assay (ANA by IFA)
Description
The ANA by IFA (Antinuclear Antibody by Immunofluorescence Assay) test identifies autoantibodies that attack the nuclei of cells, aiding in the diagnosis of autoimmune diseases such as lupus, rheumatoid arthritis, and scleroderma. It is regarded as the gold standard for ANA testing because its detailed fluorescence patterns allow for precise interpretation of these conditions.
How it works
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Sample Collection: A small blood sample is taken, and the serum (which contains antibodies) is separated.
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Incubation with Substrate: The serum is placed on a slide containing cells with visible nuclei (commonly human epithelial cells).
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Binding of Autoantibodies: If antinuclear antibodies (ANAs) are present in the serum, they will bind to the nuclei of the cells on the slide.
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Fluorescent Tagging: A fluorescent-labeled secondary antibody is added, which attaches to any bound ANAs.
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Observation: Under a fluorescent microscope, the pattern and intensity of fluorescence are examined. Different patterns (e.g., homogeneous, speckled, nucleolar) can help indicate specific autoimmune diseases.
Test Preparations
The ANA by IFA (Antinuclear Antibody by Immunofluorescence Assay) test identifies autoantibodies that attack the nuclei of cells, aiding in the diagnosis of autoimmune diseases such as lupus, rheumatoid arthritis, and scleroderma. It is regarded as the gold standard for ANA testing because its detailed fluorescence patterns allow for precise interpretation of these conditions.
