Fig. 3. Cell spreading on micropatterned substrata. A B16 mouse melanoma cell cultured for 1 hour on a patterned substratum of fibronectin. (A) Overlay of fibronectin immunofluorescence (white dots: 1 µm²; dot distance centre to centre: 5 µm) on a differential interference contrast image. The substratum determines the cell shape, resulting in a rectangular morphology. (B) Overlay of the fibronectin pattern and phalloidin staining reveals that most actin fibres terminate at fibronectin dots. Scale bar: 10 µm.