Abstract: An assay for detection of serum antibodies having specificity to hepatitis C viral antigens utilizes the carboxy-terminal 102 amino acids of the c33c region of nonstructural gene 3 of HCV containing substantially all the epitopes of the gene 3 protein. In the preferred embodiment the recombinant 102 amino acid peptide is coated onto a solid support, and incubated in the presence of serum obtained from a patient infected with HCV. The presence of antibodies bound to the antigen coated support is detected in a sandwich format utilizing a second reporter-conjugated antibody.

Abstract: A novel cDNA clone, 20E, has been isolated and characterized as encoding a previously unknown polypeptide antigen recognized by antibodies in the serum of certain patients with non-A non-B hepatitis (NANBH). The nucleic acid sequence is not represented in the genome of the Hepatitis C Virus (HCV). Neither is the nucleic acid sequence represented in the human genome. The data suggest that the RNA sequence corresponding to clone 20E is contained within the genome of an external infective agent other than HCV, and therefore may represent an additional etiologic agent or contributing factor to the development of NANBH in human patients. The 20E nucleic acid and corresponding polypeptide and respective variants thereof will be useful in a variety of procedures directed at prevention and diagnosis of NANBH.