derm); bottom 100 mm. (TIF) Small Molecules Improve Episomal Reprogramming panel: gut epithelium (endoderm). Scale bars: Figure S4 Bright-field (BF) images of an intermediate- stage colony (non-iPSC) and an iPSC colony stained positive for alkaline phosphatase. These were typical colonies observed when fibroblasts were episomally repro- grammed with small molecule-supplemented CM100 on MEF feeder cells. (TIF) PCR, RT-PCR and bisulfite- transgene NANOG (T-NANOG); Lane 3: transgene KLF4 (1) (T1- KLF4); Lane 4: transgene KLF4 (2) (T2-KLF4); Lane 5: transgene SV40LT (T-SV40LT); Lane 6: transgene SOX2 (T-SOX2); Lane 7: transgene LIN28 (T-LIN28); Lane 8: transgene c-MYC (T-c-MYC); Lane 9: endogenous OCT4 (OCT4). (TIF) Figure S3 Characterization of iPSCs derived using the small molecule-aided feeder-free condition. (A) Bright- field image of iPSCs derived from human foreskin fibroblasts (iPSF7 clone 1). Scale bar: 100 mm. (B) G-banding chromosome analysis of iPSF7 clone 1 (p18). (C) RT-PCR analysis of transgene expression in iPSC clones. NF: neonatal foreskin fibroblasts (p5); iPSF7 clone 1 to 3: iPSCs derived from neonatal foreskin fibroblasts (p26); AF: adult skin fibroblasts (p6); iPS(SK46) clone 1 to 3: iPSCs derived from adult skin fibroblasts (p22). H1ESC (p32) and piPSC (p4) derived from human foreskin fibroblasts were used as controls. T-OCT4: transgene OCT4; T-SOX2: transgene SOX2; T-NANOG: transgene NANOG; T-LIN28: transgene LIN28; T-c-MYC: transgene c-MYC; T1-KLF4: transgene KLF4 (1); T2-KLF4: transgene KLF4 (2); T-SV40LT: transgene SV40LT; OCT4: endogenous OCT4; GAPDH: endogenous control. 32 PCR cycles were used for all primer sets except for T-OCT4 (30 cycles). (D) Flow cytometry expression analysis of human ESC-specific cell surface markers (SSEA-3, SSEA-4, Tra- 1-60 and Tra-1-81) and the fibroblast-enriched marker CD44. Unfilled: isotype control; filled: antigen staining. (E) Hematoxylin and eosin staining of teratoma sections of iPSF7 clone 1. 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