Hematopoietic differentiation of human embryonic stem cells by cocultivation with stromal layers.

Human embryonic stem (hES) cells are of remarkable interest both for the utility of these cells for studying basic human developmental biology and as a potential source for novel therapeutics. Here, we provide detailed methodologies of one of the first systems used to mediate differentiation of hES cells--stromal cell coculture. Use of stromal cells adds the ability to manipulate aspects of the developmental niche that support differentiation into a defined lineage. These methods will allow efficient and reproducible development of hematopoietic progenitor cells, as well as potentially mature hematopoietic cells that are suitable for subsequent in vitro and in vivo studies.