Which diagnostic approach uses indirect immunofluorescence to reveal staining patterns in autoimmune diseases?

Which diagnostic approach uses indirect immunofluorescence to reveal staining patterns in autoimmune diseases?

• A. Western blot
• B. Indirect immunofluorescence
• C. ELISA
• D. PCR

Answer: (B)

Indirect immunofluorescence uses the patient’s autoantibodies to bind to antigens on a cellular substrate, and then a fluorescent secondary antibody detects those bindings to reveal staining patterns under a fluorescence microscope. This pattern-based readout, typically on fixed cells such as HEp-2 cells, is exactly how ANA screening and other autoimmune antibody tests are interpreted, because the shape and location of the staining (nuclear, cytoplasmic, nucleolar, etc.) point toward specific autoantibody groups. The visualization is achieved with a fluorophore-labeled secondary antibody, so the signal arises indirectly through the secondary detector rather than directly labeling the patient antibodies themselves. Western blot, ELISA, and PCR detect different things: Western blot identifies specific proteins after separation by electrophoresis, ELISA uses enzyme-labeled detection in a plate without fluorescence pattern visualization, and PCR detects genetic material.

Indirect immunofluorescence uses the patient’s autoantibodies to bind to antigens on a cellular substrate, and then a fluorescent secondary antibody detects those bindings to reveal staining patterns under a fluorescence microscope. This pattern-based readout, typically on fixed cells such as HEp-2 cells, is exactly how ANA screening and other autoimmune antibody tests are interpreted, because the shape and location of the staining (nuclear, cytoplasmic, nucleolar, etc.) point toward specific autoantibody groups. The visualization is achieved with a fluorophore-labeled secondary antibody, so the signal arises indirectly through the secondary detector rather than directly labeling the patient antibodies themselves.

Western blot, ELISA, and PCR detect different things: Western blot identifies specific proteins after separation by electrophoresis, ELISA uses enzyme-labeled detection in a plate without fluorescence pattern visualization, and PCR detects genetic material.