a) Cell-capture efficiency of the integrated CTC-capture device at flow rates of 0.5, 1, 2, 3, 5 and 7 mL h−1. Error bars show standard deviations (n = 3). 1.0-mL Cell suspensions containing EpCAM-positive MCF7 breast cancer cells (100 cells mL−1) were employed as a model system. The error bars of the first three data points are very small. Spatial distribution of substrate-immobilized MCF7 cells along the serpentine microchannels at different flow rates of b) 1, c) 2, and d) 7 mL h−1.