Figure 3. De novo immortalized fibroblasts (tKM cells) cannot be reprogrammed to iPSCs.
Representative images of cell colonies derived from tKM cells and, for control, MEFs, revealed by AP-staining (A) or by immunostaining for Nanog (green) and SSEA1 (red) (B) on day 14 after OKSM lentivirus infection. Cells were counterstained with DAPI (blue). tKM-derived clones are rare, notably larger, and have very low adhesion to plastic surface, compared to MEF-derived clones. (C) Counts of AP- and Nanog-positive cell colonies derived from MEFs and tKM cell; results are expressed as mean ± SD, n = 2.