Patent ID: 8492149

Claim:
A method of producing spherical neural masses from human embryonic stem cells, comprising the steps of: (a) culturing human embryonic stem cells for 5 to 21 days to obtain embryoid bodies and removing cystic embryoid bodies having hollow ball morphology from the embryoid bodies; (b) attaching the resultant embryoid bodies to the surface of a culture dish coated with Matrigel, laminin, or L-polyornithine, and culturing them in media containing 0.5×N-2 supplement for 5 to 7 days to inhibit the growth of cells other than neural progenitors; (c) culturing the resultant culture for 3 to 7 days in media containing N-2 and bFGF; (d) dissecting and isolating neural structures having neural rosette or neural tube morphology from the resultant culture in step (c); (e) culturing in suspension the neural structures in media containing N-2 and bFGF to obtain spherical neural masses, wherein the spherical neural masses have expanded neural structures and spherical morphology, and express Nestin, Sox1 and Pax6; (f) removing spot-forming fibroblast-like cells and cystic structures, which are generated during step (e), and isolating only the expanded neural structures in the spherical neural masses; and (g) repeating step (e) and step (f) at least four times to increase a purity of the spherical neural masses and expand the spherical neural masses.