Hepatitis C virus (HCV) is a recently discovered major human pathogen infecting 170 million individuals worldwide. It was the first hepatotropic virus to be isolated by molecular biology techniques. Since its discovery in 1989 considerable progress has been made in the identification of the viral functional regions, the interactions between viral products, and viral pathogenesis. However, little is known about its replication cycle and the only experimental in vivo HCV infection model is limited to the chimpanzee. Thus, the development of a cheap and accessible in vitro or in vivo culture system has become a priority. The work in this thesis explores a variety of different approaches to an in vivo culture system using the severely combined immunodeficient (SCID) mouse. These animals lack functional T and B cells and will accept xenografts from a range of species including humans. Hepatocyte derived cell lines and primary human hepatocytes (PHHC) were transplanted intrasplenically and under the renal capsules after performing a partial hepatectomy. The rationale rests on the hypothesis that these cells would attain a biologically functional state of differentiation in vivo, increasing their sensitivity to HCV infection and acting as targets for HCV replication in an in vivo culture system. HCV positive serum was used to infect the cells prior to transplantation or 3 days post transplantation. PHHCs were also mixed with anti- met antibody and interleukin 6 (IL6) prior to transplantation to increase their survivability and proliferation in vivo; silica was administered intraperitoneally to deplete host macrophage cells. All the animals transplanted with hepatocyte derived cell lines developed extremely large metastatic tumours which were hemorrhagic, additionally these cells were not susceptible to HCV infection, irrespective of the route of infection and source of the HCV positive serum. PHHCs failed to engraft irrespective of treatment and were HCV reverse transcription polymerase chain reaction (RTPCR) negative