the effect of murine leukemia inhibitory factor on in vitro differentiation of mouse embryonic stem cells

background: embryonic stem cells (esc) are pluripotent cells which have been used as a model to study the mechanism that control the embryogenesis and early mammalian development in vitro. the aim of this study was to isolate and produce embryonic stem cells from late blastocyst stage embryos in mice. materials and methods: blastocyst stage embryos from pregnant nmri mice were obtained and cultured for 24 h in dmem medium. 4-6 days after hatching, the inner cell masses (icm) formed colonies which were then collected mechanically and trypsinized. several subcultures were prepared in the medium supplemented with 0.1 mm 2 mercaptoethanol, 1000 u/ml leukemia inhibitory factor (lif) and 10% fetal bovine serum (fbs). the (esc) were recognized by alkaline phosphates histochemistry using azo-coupling method. results: the results demonstrated that a highly pluripotent stem cell line was derived from the blastocyst stage embryos of nmri mice; however, the rate of colonies was as low as 10%. conclusion: the lif is effective to culture and maintain the isolated icm colonies in undifferentiated condition in the absence of feeder layer.