Fig. 2

Enrichment of OKSM by FACS generates phenotypic iPS colonies. a Schematic for reprogramming with sorting enrichment, with the FACS enrichment occurring on day 5.5. b Reprogramming efficiency of sorted cells. N > 4 for each condition. Original unmodified Yamanaka episomal plasmids, NE non-enriched, OKSM cells reprogrammed using our tagged episomal vectors. p value determined by Mann–Whitney t test. Non-significant (ns) values left to right: p = 0.13, p = 0.37; **p = 0.002. c Immunohistochemistry for pluripotency markers on iPS cell colonies from quadruple-positive OKSM sorts showing positivity for markers: Oct3/4, alkaline phosphatase (AP), and Tra-1-60. Cells were stained at passage 8 (approximately day 60 post transfection). d Episomal-derived iPS cell embryoid body (EB) formation. iPS cells were transitioned from feeders to Matrigel and finally into EB differentiation media. Top: iPS cells on SNL feeder cells. Middle: iPS cells transitioned to feeder free conditions. Bottom: EBs at day 8 of differentiation. Scale bar = 200 μm. e Hematoxylin and eosin staining of teratoma sections showing representatives of the three germinal layers (yellow arrows). Scale bar = 200 μm (Color figure online). iPSC induced pluripotent stem cell, OKSM Oct3/4 + shp53, Klf, Sox2, and L-Myc + Lin28