Figure 1: Induction of human iPSCs after reprogramming by combining transgene Oct4, Klf4, Sox2, and c-Myc. (A) Images of iPS colonies and positive staining for alkaline phosphatase. (B) Expression levels of endogenous and exogenous OCT4, SOX2, Klf4, and c-myc (relative to Actin) assessed by RTPCR. (C) Staining of iPS colonies was positive for a panel of pluripotent markers: TRA-1-60, SSEA-4, Oct4, Nanog, TRA-1-81 expression. (D) Hematoxylin and eosin staining showed teratoma formation from hiPS cells containing multiple tissues and positively immunostaining for α-actin (mesoderm marker), α-fetoprotein (endoderm marker), and β-tubulin (ectoderm marker).