Anti MPO (p-ANCA) ELISA Assay Kit is based on the binding of the antibodies in the sample to the human neutrophil myeloperoxidase coated on the microplates. In the first step the antibodies in calibrators, controls or prediluted samples bind to the inner surface of the wells. After a 60 minutes incubation the microplate is washed with a wash buffer to remove the non-reactive serum components. In the second step an anti-human-IgG horseradish peroxidase conjugated solution recognizes the IgG class antibodies bound to the immobilized Antigenss. After a 30 minutes incubation any excess of enzyme conjugate which is not specifically bound is washed away with the wash buffer. Then a chromogenic substrate solution containing TMB is dispensed into the wells. After 15 minutes of incubation the color development is stopped by adding the stop solution. The solutions color change into yellow. The amount of color is directly proportional to the concentration of IgG antibodies present in the original sample. The concentration of IgG antibodies in the sample is calculated through a calibration curve. Sample Types: serum, plasma. Range: 10 - 160AU/mL. Sensitivity: 0.73 AU/mL. Time: 2 hours ? PR3- ANCA is the classical autoAntigens in Wegener s granulomatosis with a clinical specificity of more than 95%. c-ANCA is documented to be present in different diseases. Anti-MPO antibodies are highly specific for idiopathic and vasculitis associated crescentic glomerulonephritis and also for classic polyarteritis nodosa, Churg-Strauss syndrome and the polyangitis overlap syndrome without renal involvement.7-10 With respect to sensitivity, either MPO or PR-3 antibodies were found in 77 to 100% of patients with idiopathic and vasculitis associated crescentic glomerulonephritis. In WG, anti-MPO antibodies were detected only occasionally and generally in patients negative for PR-3 antibodies.