Cell cycle distribution in Capan-2 spheroids expressing the Fucci-Red or -Green reporters. (A, C): Visualization of the G1 and S-G2 cells on a frozen section of a large Capan-2 spheroid expressing the Fucci-red and Fucci-green reporters respectively. Nuclei are stained with DAPI (blue). Scale bar: 50 μm. (B, D): Graphic representations of the percentage of cells expressing the Fucci-red or Fucci-green reporters related to the distance to spheroid surface within Capan-2 MCTS measuring 340 μm +/− 20 μm (top) or 580 μm +/− 20 μm (bottom) in diameter. The relative position of the spheroid center is indicated. Data correspond to the mean+/−SEM of percentage of positive cells on 7-10 sections from 3-4 different spheroids.