Scientific Journal of

  Abstract

 Background and Objectives

 In-vitro differentiation of embryonic stem cells to different cell types provides a valuable tool to study the interaction between these cells and growth factor. Recent investigation showed that recognition of the factors and their influence on the hematopoiesis is important. The aim of this research was to study the effect of different dose of EPO and BMP4 on the differentiation of embryonic stem cells the number and size of total colonies and benzidine positive colonies were also evaluated.

 Materials and Methods

 4-day-old EBs were trypsinized and dissociated to single cells. These cells were cultured on the semisolid medium in two groups with different doses of EPO (10, 20, 40, 80, 160 ng/ml) and BMP4 (5, 10, 20, 40, 80, 160 ng/ml). The colonies were evaluated after 10 days and stained with benzidine and giemsa.

 Results

 The size of colonies in all concentrations of EPO and BMP4 faced an increase showing a significant difference with the control group (P ≤ 0.05). Total number of colonies had a negative correlation with the dose of BMP4 but there was not any significant difference between benzidine positive colonies with the control group. The number and percentage of benzidine positive colonies had significant difference with the control group in all doses of EPO. 20ng/ml of EPO contrary to other concentrations of EPO caused increase in benzidine positive colonies.

 Conclusions

 Our results showed that EPO had better effect on ES cells erythroid colony differentiation than BMP4. It also indicated that 20 ng/ml of EPO was the best concentration.

 �

 Key words : Embryonic stem cell, Bone Morphogenetic Protein4, Erythropoietin