The precursor cells for oligodendrocytes were first discovered in 1993 by Raff, Miller and Noble and have been extensively studied. These precursor cells are referred in the literature as either oligodendrocyte-type-2 astrocyte progenitor cells or oligodendrocyte precursor cells (OPC). The developing and adult central nervous system both contain OPC. Oligodendrocytes, the myelin-forming cells of the central nervous system, develop from OPC. In culture, OPC can be generated from neural progenitors or neural stem cells in the presence of basic fibroblast growth factor and they proliferate in presence to platelet-derived growth factor or factors produced by astrocytes and differentiate into mature oligodendrocytes. Because of this, they have provided an exceptional population in which to study developmental transitions. HOPC-os from AcceGen Biotech Research Laboratories are isolated from human oligodendrocyte precursor cell cultures. HOPC-os are cryopreserved and delivered frozen. Each vial contains >1 x 10^6 cells in 1 ml volume. HOPC-os are characterized by immunofluorescent method with antibodies to A2B5 and nestin. HOPC-os are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HOPC-os are guaranteed to further culture at the condition provided by AcceGen Biotech Research Laboratories.