Method Description

The ORTHO HCV (hepatitis C virus) Version 3.0 ELISA (enzyme-linked immunosorbent assay) Test System is a 3-stage test carried out in a microwell coated with a combination of recombinant HCV antigen (c22-3, c200, and NS5). In the first stage, a diluted test sample or appropriate controls are incubated in the test well for a specified length of time. If antibody reactive to any of the 3 antigens is present in the specimen, antigen-antibody complexes will be formed on the microwell surface. If anti-HCV is not present, complexes will not be formed. In the subsequent washing step, unbound serum proteins will be removed. In the second stage, murine monoclonal antibody conjugated to horseradish peroxidase is added to the microwell. The conjugate binds specifically to the human IgG portion of the antigen-antibody complexes. If antigen-antibody complexes are not present, the unbound conjugate will be removed by subsequent washing. In the third stage, an enzyme detection system composed of o-phenylenediamine (OPD) and hydrogen peroxide is added to the test well. If bound conjugate is present, the OPD will be oxidized, resulting in a colored end-product. In this reaction, peroxidase is divalently oxidized by hydrogen peroxide to form an intermediate compound, which is, in turn, reduced to its initial state by subsequent interaction with hydrogen ion donating OPD. The resulting oxidized form of OPD has an orange color. Sulfuric acid is then added to stop the reaction. The color intensity is dependent upon the amount of bound conjugate and is a function of the concentration of anti-HCV present in the specimen. The color intensity is measured with a microwell reader (photometer) designed to measure light absorbance in a microwell. (Package insert: Hepatitis C Virus Encoded Antigen [Recombinant c22-3, c200, and NS5], ORTHO HCV Version 3.0 ELISA Test System. Ortho Clinical Diagnostics; 01/2022)