Inclusion Criteria:  Anonymized or pseudo-anonymised leftover ethylenediaminetetraacetic acid (EDTA) plasma/serum samples from  Males or females Aged ≥18 years of age  Belonging to one of the following enrollment groups  Unselected blood donor Hospitalized patient from GI, hepatology, Internal Medicine or Infectious Disease services Known HCV Ab positive (by Immunoblot) at different stages of disease with at least 1.5 mL leftover sample (without genotype or PCR on same draw) OR at least 0.8 mL leftover sample (with genotype or HCV PCR on same draw)  Exclusion Criteria:  Samples from subjects already included in the study