Fig 1. Design of microfluidic chip for tumor spheroid-fibroblast co-culture.

Structure and organization of a microfluidic chip used for 3D co-culture of human colorectal cancer cells (HT-29) and normal colorectal fibroblasts (CCD-18Co). One chip contained 4 units and one unit consisted of 7 channels for either cell loading or media fill. Channel designation for co-culture: cancer cells and fibroblast cells were loaded in channel 4 and 2, respectively, and other channels (1 and 3) were used for media fill. A cell loading channel is shown with detailed structure and dimension (left-bottom).