Abstract: Polypeptide antigens are disclosed which are immunoreactive with sera from individuals having a non-A, non-B, non-C, non-D, non-E Hepatitis, herein designated Hepatitis G Virus (HGV). Corresponding genomic-fragment clones containing polynucleotides encoding the open reading frame sequences for the antigenic polypeptides are taught. The antigens are useful in diagnostic methods for detecting the presence of HGV in test subjects. The antigens are also useful in vaccine and antibody preparations. In addition, the entire coding sequences of two HGV isolates are disclosed. Methods are presented for nucleic acid-based detection of HGV in samples and also methods for the isolation of further genomic sequences corresponding to HGV.

Abstract: A peptide of the formula (SEQ ID NO:1) Met Ser Thr Ash Pro Lys Pro Cys Arg Lys Thr Lys Arg Asn Thr Asn Arg Arg Pro Cys Asp Val Lys Phe Pro Gly Gly, Gly wherein there is a disulfide bridge between the two cysteine residues, is described. Further, a diagnostic antigen in carrier-bound form comprising said peptide is disclosed. Said peptide may be used in a method of in vitro diagnosing an active infection caused by hepatitis C virus.