In vitro differentiation of mouse embryonic stem cells into primitive blood vessels

Mouse embryonic stem (ES) cells, derived from the inner cell mass of blastocyst stage embryos, undergo programmed differentiation in vitro to form a primitive vasculature. This programmed differentiation proceeds through similar processes of vasculogenesis and angiogenesis found during early vascular development in vivo. Partially differentiated ES cell clumps or embryoid bodies (EBs) first form blood islands that are subsequently transformed into a network of primitive blood vessels that contain lumens. Therefore, vascular differentiation of ES cells is an ideal model to study and manipulate early vascular development. Here we provide protocols for the routine maintenance of mouse ES cells and in vitro differentiation. We also include protocols for establishing transgenic ES cell lines and visualization of blood vessels by use of endothelial specific molecular markers.