Fig. 5. Representative TRA-1–60 immunostaining.

3 × 10³, 10 × 10³, and 30 × 10³ dermal fibroblasts derived from a patient with Down syndrome were reprogrammed and stained for the pluripotency marker TRA-1–60. For this cell line, the most robust reprogramming was achieved in the 10 × 10³ cell-seeding condition. Plating 3 × 10³ fibroblasts was sub-confluent with observable barren patches throughout the well by the end of reprogramming. Seeding 30 × 10³ fibroblasts became over-confluent, which also inhibited reprogramming efficiency