Figure 1: The method for grafting putative mouse and human definitive endoderm derived from embryonic stem cells to chick embryos. (A-D) The procedure of moving the chick embryo from the egg to the agar-albumen substrate using a filter paper carrier. (E) An illustration showing the positioning of grafted DE in the chick embryo, which is cultured ventral side up. (F) Grafting of stained DE into the chick embryo. Inset: fluorescently labeled DE (CMTMR= CellTracker™ Orange dye). (G-H) Transplanted embryo 48 hours post grafting. The arrowheads point at sites of integration. A=anterior, D=Dorsal, P=posterior, V=Ventral.