Generation of protein-iPS cells from c-kit⁻ cardiac fibroblasts. (A) Gene and surface protein expression of c-kit⁻ and c-kit⁺ cells (immediately after magnetic sorting). (B) Reevaluation of surface protein expressions on fourth-passage c-kit⁻ cardiac fibroblasts. (C) Fibroblasts were reversibly permeabilized, incubated with 70 kDa Texas Red–conjugated dextran and resealed. Serial fluorescent images. (D) Confocal images at day 7. (E) Time line of reprogramming by proteins. Colonies developed on days 4 to 7. DMEM/HG, DMEM with high glucose (D-glucose; 4500 mg/L). (F) Phase-contrast bright-field morphology of cells and colonies. (G) ALP staining of authentic ES cell, cFB-protein-iPS cell, and adult cardiac fibroblast. (H) Immunocytochemistry showing that cFB-protein-iPS cells express SSEA1 and Oct4 but not SSEA4 (a known human ES cell marker).