Pluripotency of bioreactor differentiated cells as shown by tumor formation in SCID mice. A) The 125-mL NDS stirred-suspension bioreactor. B) Sections of teratoma generated from non-drug selected pluripotent mESCs in bioreactor showing cells from all three germ layers: (Star) Mesoderm; (Circle) Ectoderm; (Triangle) Endoderm (H&E staining). C) Teratoma derived from mESCs after differentiation under static culture system. The majority of teratoma contains unorganized tissue. Only some gut-like epithelial cells were recognizable (Square).