text_1: Pure neural progenitor cell (NPC) populations can only be obtained from cell cultures that undergo passaging, filtration, or other isolation and cell sorting methods.
text_2: Here we demonstrate that the complex neurosphere environment is dispensable for stem cell maintenance, and that the combination of fibroblast growth factor 2 (FGF-2) and epidermal growth factor (EGF) is sufficient for derivation and continuous expansion by symmetrical division of pure cultures of neural stem (NS) cells.