Food extracts of the dedicated panel are embedded in nitro-cellulose strip membranes. For testing, a diluted sample (serum or plasma) is added to the incubation tray. Specific IgG₄ antibodies of the sample bind to the spotted antigens on the membrane during incubation, and non-bound components of serum or plasma are washed away after incubation. Subsequently, anti-human IgG₄ antibodies coupled horseradish peroxidase is added and bind to the IgG₄ antibodies of the sample and the standards. Then the unbound detection antibodies are washed away. The color substrate TMB (3,3‘,5,5‘-tetramethylbenzidine) is added, which is converted by the horseradish peroxidase conjugate. The reaction is stopped by adding a stop solution. A dark colored dye is formed and the respective intensity correlates with the proportional amount of locally-bound antibody.The identified kUA/L can be assigned to the respective intensity and provide the level of specific IgG₄ sensitization (See table below).