Abstract: A method for replication of hepatitis C virus genome comprising infecting animal cells that have been infected with mouse retrovirus, with hepatitis C virus, and then culturing those cells. The present invention further provides a method for distinguishing a hepatitis C virus with high infectivity and a hepatitis C virus with less infectivity, comprising centrifugating a sample comprising a virus to be tested in a liquid medium to determine the density of the virus, and assigning the virus to a hepatitis C virus with high infectivity it the density thereof is up to about 1.06 g/ml, and assigning the virus to a hepatitis C virus with less infectivity if the density thereof is at least 1.

Abstract: A method for replication of hepatitis C virus genome comprising infecting animal cells that have been infected with mouse retrovirus, with hepatitis C virus, and then culturing those cells. The present invention further provides a method for distinguishing a hepatitis C virus with high infectivity and a hepatitis C virus with less infectivity, comprising centrifugating a sample comprising a virus to be tested in a liquid medium to determine the density of the virus, and assigning the virus to a hepatitis C virus with high infectivity if the density thereof is up to about 1.06 g/ml, and assigning the virus to a hepatitis C virus with less infectivity if the density thereof is at least 1.