To test for antibodies to specific allergens, which procedure would be performed?

To test for antibodies to specific allergens, which procedure would be performed?

• A. RAST
• B. ELISA
• C. Western blot
• D. Immunofluorescence

Answer: (A)

To determine if a person has antibodies against specific allergens, you want to detect IgE antibodies that recognize those allergens. The RAST approach does exactly this by immobilizing the allergen, exposing it to the patient’s serum, and then using a radiolabeled anti-IgE to detect any IgE that has bound to the allergen. The amount of radioactivity measured reflects how much of that specific IgE is present, giving a direct readout of sensitization to that allergen. Immunofluorescence is used to detect antibodies bound to cells or tissue sections with fluorescent labels, not to quantify serum allergen-specific IgE. Western blot identifies antibodies to particular proteins after separation by gel electrophoresis, more of a protein-characterization tool than a routine test for allergen-specific IgE. ELISA can measure various antibodies, and there are ELISA-based tests for specific IgE as well, but the classic procedure described for testing antibodies to specific allergens is the radiolabeled IgE-binding assay used in RAST.

To determine if a person has antibodies against specific allergens, you want to detect IgE antibodies that recognize those allergens. The RAST approach does exactly this by immobilizing the allergen, exposing it to the patient’s serum, and then using a radiolabeled anti-IgE to detect any IgE that has bound to the allergen. The amount of radioactivity measured reflects how much of that specific IgE is present, giving a direct readout of sensitization to that allergen.

Immunofluorescence is used to detect antibodies bound to cells or tissue sections with fluorescent labels, not to quantify serum allergen-specific IgE. Western blot identifies antibodies to particular proteins after separation by gel electrophoresis, more of a protein-characterization tool than a routine test for allergen-specific IgE. ELISA can measure various antibodies, and there are ELISA-based tests for specific IgE as well, but the classic procedure described for testing antibodies to specific allergens is the radiolabeled IgE-binding assay used in RAST.