HHSEC are isolated from human liver. HHSEC are cryopreserved immediately after purification and delivered frozen. Each vial contains >5 x 10^5 cells in 1 ml volume. HHSEC are characterized by immunofluorescent method with antibodies to vWF/Factor VIII and CD31 (P-CAM). HHSEC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HHSEC are guaranteed to further expand for 15 population doublings in the conditions provided by Creative Bioarray.