Figure 1.

Schematic diagram of the experimental design. Human fetal femur-derived skeletal cells were cultured in chondrogenic medium in an in vitro three-dimensional pellet culture system for 21 days. From the same fetal sample: (i) cells were cultured over 21 days in the absence of live-imaging (control); (ii) cells were cultured over 21 days and live-imaging performed at day 7; and (iii) cells were cultured over 21 days and live-imaging performed at day 7 and day 21. The expression of skeletal lineage-specific genes after 21 days in chondrogenic culture was analysed for all three conditions.