Fig. 1

Reprogramming of human fibroblasts into induced pluripotent stem cells. a, b Fibroblast cells immunolabeled with antibodies against FSP-1 (a, green) or vimentin (b, red). DAPI (blue) was used to counterstain the nuclei. c–e iPSCs immunolabeled with antibodies against NANOG (c), SOX2 (d), and OCT4 (e). Expression of these proteins indicates the identity of iPSCs derived from fibroblast reprogramming. f Normal karyotype of an iPSC line determined by G-banding. g Results from PluriTest assay show that our iPSCs have a pluripotent signature (high pluripotency score and low novelty score), and cluster with well-characterized bona-fide iPSC and ESC lines (red background hint; iPSC line 2 is indicated by a yellow arrowhead in the magnified panel) and not with partially differentiated pluripotent cells or somatic tissue (blue background hint). Scale bars: a, b, 50 μm; c–e, 20 μm. FSP-1 fibroblast-specific protein-1