This invention provides a system for efficiently producing differentiated
cells from pluripotent cells, such as human embryonic stem cells. Rather
than permitting the cells to form embryoid bodies according to
established techniques, differentiation is effected directly in monolayer
culture on a suitable solid surface. The cells are either plated directly
onto a differentiation-promoting surface, or grown initially on the solid
surface in the absence of feeder cells and then exchanged into a medium
that assists in the differentiation process. The solid surface and the
culture medium can be chosen to direct differentiation down a particular
pathway, generating a cell population that is remarkably uniform. The
methodology is well adapted to bulk production of committed precursor and
terminally differentiated cells for use in drug screening or regenerative
medicine.