A rotating wall vessel is used as a culture vessel and bioreactor for the cultivation of hepatocytes in the form of spheroids to generate a culture with many properties of the intact liver. These properties include enzyme activity comparable to fresh cells and long-term maintenance of viability and cellular function for periods on the order of months. The cultures may be used to produce hepatocyte products, evaluate metabolism of an agent, propagate Hepatitis C virus and test agents as inhibitors of this virus. Thus, the culture system disclosed herein makes long term functional cultivation of human hepatocytes feasible.