Before serum samples are tested using the SPOT Test technology they are first pre-treated to enhance accuracy and reliability. These immunosorbant procedures significantly lower the concentration of competing antibodies. IgG INTERFERENCE: Upon exposure to antigen, the body produces antibody (IgE and IgG) with IgG being produced in larger quantities. This circulating IgG interferes with the assay. To counter this problem all serum samples are first absorbed with Staphylococcal protein A extracted from the cell wall of S. aureus. This protein has a strong binding affinity to the Fc portion of the IgG molecule thus removing it from the serum.   NON-SPECIFIC IgE INTERFERENCE: The high levels of allergen non-specific IgE are usually caused by parasitic infections in animals. Allergen non-specific IgE competes with allergen specific IgE for binding, thus skewing the results. This problem is resolved by absorbing serum samples with helmenthes antigens. Helmenthes are one of the most common antigens responsible for high IgE levels. The effect of this absorption is to lower the oeverall concentration of interfering allergen non-specific IgE.