Fig. 10. Quantification of dot usage. B16 cells were cultured for 1 hour on patterned substrata and labelled for fibronectin (FN), actin (act) and phosphotyrosine (PT) or paxillin (Pax). The area covered by phosphotyrosine (A) or paxillin (B) was measured for focal adhesions in the cellular periphery for cells growing on homogeneous substrata (hs) and on patterned substrata with three different dot sizes (contact size, ) and set in relation to the underlying fibronectin area (dot usage, ). Dot usage was also determined for focal adhesions formed on patterned substrata with 12 µm² dots and variable distances. Bars represent s.e.m.