This in vitro test measures IgE antibodies directed against specific allergens like skin testing, but is used to quantitatively measure specific IgE levels in serum. RAST can be used in the case of potential medication interference or when skin testing is either infeasible or yields ambiguous results. RAST, or the Radioallergosorbent Test, operates on the principle of traditional antibody assays except that the solid phase (bead or disc) is coated with allergen. Patient serum is first added and incubated with the bead-bound allergen. Unbound antibody is then washed away followed by addition of radiolabeled anti-IgE antibody. Unbound radioactivity is washed free of the bead and then the radioactivity is counted to determine how much IgE in patient serum has bound compared to a standard and to normal controls.

Immunological Techniques
University of Arizona
Monday, October 6, 2008
douglas.lake@asu.edu

All contents copyright © 2008. All rights reserved.