Cytokine requirements differ for stroma and embryoid body-mediated hematopoiesis from human embryonic stem cells.

Objective: Human embryonic stem (ES) cells can be induced to differentiate into hematopoietic lineages either by stromal cell coculture or by formation of embryoid bodies (EBs). Here, we better characterize cell-bound and secreted factors that support this hematopoietic development.

Methods: Human ES cells either cocultured on the mouse bone marrow cell line S17, or allowed to form EBs, were induced to differentiate in the presence of serum, serum-free conditions, and serum-free media supplemented with defined cytokines.