Human embryonic stem cells (hESCs) represent an important resource for novel cell-based regenerative medical therapies. hESCs are known to differentiate into mature cells of defined lineages through the formation of embryoid bodies (EBs) which are amenable to suspension culture for several weeks. However, EBs derived from hESCs in standard static cultures are typically non-homogeneous, leading to inefficient cellular development. Here, we systematically compare the formation, growth, and differentiation capabilities of hESC-derived EBs in stirred and static suspension cultures. A 15-fold expansion in total number of EB-derived cells cultured for 21 days in a stirred flask was observed, compared to a fourfold expansion in static (non-stirred) cultures. Additionally, stirred vessel mediated cultures have a more homogeneous EB morphology and size. Importantly, the EBs cultivated in spinner flasks retained comparable ability to produce hernatopoietic progenitor cells as those grown in static culture. These results demonstrate the decoupling between EB cultivation method and EB-derived cells' ability to form hematopoietic progenitors, and will allow for improved production of scalable quantities of hematopoietic cells or other differentiated cell lineages from hESCs in a controlled environment. (c) 2006 Wiley Periodicals, Inc.