The RadioAllergoSorbent Test (RAST) may be requested when a specific allergy is in question. It gives an indication of antibodies to a specific “trigger” antigen, such as pollen or house-dust mite.
How the Test is Performed
RadioAllergoSorbent Test (RAST) is a blood test and therefore requires a blood sample from a vein.
Medical Conditions and Symptoms
Your doctor may request a RadioAllergoSorbent Test (RAST) in the event of severe allergy, asthma or hayfever, where the precipitating substance (known as an antigen) is not clear. A subgroup of antibodies called IgE antibodies are strongly associated with the abnormal immune system response in allergic reactions. Amongst these IgE antibodies, allergen-specific IgE antibody numbers can be measured by the RAST test.
Test Results Explained
RadioAllergoSorbent Test (RAST) results are given in terms of an antibody TITRE.
Related Specialists
Related Procedures
- Blood Test (venesection)
Related Tests
- Differential White Cell Count (Diff)
- Respiratory Function Tests (RFTs)
- Peak Expiratory Flow Rate (PEFR)
Also Known As
- Allergen-specific IgE antibody test




