Radioallergosorbent test (RAST)

An in vitro or test tube assay used to identify and quantitate potential allergen-specific IgE antibodies in patient serum or potential allergens from product extracts. Typically, a protein allergen is bound to a surface such as a plastic well. The patients serum is added to the well. If the serum contains antibody to the allergen, the antibodies and allergen will attach to each other. The level of attachment is measured and the amount quantified. Alternatively, IgE antibodies are bound to the plate surface. Then an extract of a product, such as a natural rubber latex glove, is added to the plate to determine if allergens are present in the tested product.