Figure 2From: Generation of human induced pluripotent stem cells by simple transient transfection of plasmid DNA encoding reprogramming factorsAnalysis of pluripotency of iPS cells generated by plasmid transfection. A) Micrographs comparing the morphology of the plasmid-derived iPS cells (iPSK3) and human ES cell line H9.14 cultured on mitotically inactivated MEFs and alkaline phosphatase activity identified by histochemistry (Scale bar = 100 μm). B) Immunostaining revealing the presence of OCT4 (red) and SSEA4 (green) in plasmid-derived iPSK3 cells and control H9 human ES cells. Cell nuclei were detected using DAPI stain (Blue) (Scale bar = 100 μm). C) Representative FACS analysis demonstrating that ≥ 99% of iPSK3 cells in culture (passage 8-10) express markers of pluripotency including OCT4, SSEA4, TRA1-60 and TRA1-81. Cells expressing the fibroblast marker CD13 were not detected. D) Micrographs of H & E stained sections through teratomas that formed from iPSK3 cells after injection into immune deficient mice. Cell types derived from all three germ layers - ectoderm, endoderm and mesoderm (indicated with *) - were detected (Scale bar = 100 μm). E) Karyotype of iPSK3 cells revealed a normal distribution of 46 chromosomes with XY sex chromosomes. Chromosomal rearrangements were not detected by G-banding. F) STR analyses using CODIS primers demonstrated that the DNA fingerprint of iPSK3 cells was indistinguishable from that of CRL2097 foreskin fibroblasts used as recipients for reprogramming.Back to article page