human hepatocytes are isolated from human liver. HH are cryopreserved immediately after purification and delivered frozen. Each vial contains >1 x 10^6 cells in 1 ml volume. HH are characterized by immunofluorescent method with antibodies to albumin, cytokeratin-18 and vimentin. HH are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HH is not recommend for expanding or long term cultures since the cells do not proliferate in culture.