An in vitro method that allows detection of hepatitis C by detecting hepatitis C virus (HCV) core protein and antibodies to HCV core protein (anti-core antibodies) in a single assay is provided. Cross-reactivity is eliminated in the method preferably by utilizing short peptides, each of which has an amino acid sequence that corresponds to an immunodominant region of the native core protein but which does not wholly encompass the epitope bound by the antibodies utilized in the method. The method can be used to detect the presence of HCV in a subject, and/or to determine the suitability of donor blood or blood products for transfusion purposes. Also provided are diagnostic kits for carrying out the method and a process for selecting suitable capture peptides and monoclonal antibodies for use in the combination method.
