AbstractWe applied serum‐free cell culture methods that allow extended proliferation of mouse astrocyte precursor cells to the multipassagc culture of embryonic human brain cells. Cells were cultured in nutrient medium supplemented with insulin, transferrin, epidermal growth factor, fibreblast growth factor, heparin, high‐density lipoprotein, and fibronectin. Cultures were maintained for a maximum of 70 population doublings before proliferation ceased. The cells synthesized glial fibrillary acidic protein, an astrocyte marker, and expression of this protein was increased by incubation of the cells with transforming growth factor beta or serum. These results identify extracellular factors important for proliferation and differentiation of embryonic human astrocytes and provide a controlled system for multipassage cult