The Chorus devices are ready to use for the detection of allergen-specific IgE antibodies, in the Chorus TRIO instruments. The test is based on the ELISA principle (Enzyme linked Immunosorbent Assay). Anti-human IgE monoclonal antibody is bound to the solid phase. The specific immunoglobulins are bound to the antibody through incubation with diluted human serum. After washing to eliminate the proteins which have not reacted, incubation is performed with the biotynilated conjugate. The biotynilated conjugate is eliminated and the Streptavidin-Peroxidase conjugate is added. The unbound conjugate is eliminated and the peroxidase substrate is added. The enzymatic reaction is stopped by the adding of the Stop Solution, which makes the solution turn to yellow. The colour which develops is proportional to the concentration of specific antibodies present in the serum sample. The disposable devices contain all the reagents to perform the test in the Chorus TRIO instruments. The results are expressed in Units (KU/L).