Fig. 5. (A) Topograph and 3D-reconstruction of a cluster of four FAs. Cross sections along the indicated lines (bisecting FAs perpendicularly) were taken. (B) Height profiles corresponding to the cross sections taken in (A). The average height of bisecting cross sections corresponds to 84±16 nm (average height), whereas the filamentous structures extended over the substratum by 118±27 nm. The dashed lines indicate the average values generated from analysis of more than 30 FAs. (C) Histogram showing the distribution of distances between neighboring filament/filament bundles (>30 FAs analyzed). The mean spacing between filaments/filament bundles at the FA half-length was 127±50 nm.