Fig. 2. Density dependence of 3T6 alignment on r = 60 μm patterns with 1.5 μm tall ridges. (a) Angle , measuring the deviation from the ideal alignment, as a function of the average density of cell monolayers. Every point corresponds to the observation of cells near one defect, either positive (red crosses) or negative (blue circles). (b) Details of fibroblasts near a positive defect in a monolayer with density 1400 cells per mm², showing good alignment. (c) Detail of fibroblasts near a positive defect with density 1700 cells per mm², showing a smaller aspect ratio and worse alignment. For n = 30 negative defects and n = 39 positive defects, we observe a difference in the quality of alignment between cells with a density typically >1400 cells per mm² and with a density <1400 cells per mm², with p-value < 0.0001.