Top view and side view iPALM images of focal adhesions (white boxes, top-view panels) and corresponding z histograms and fits. a, b, FAK–tdEos; c, d, paxillin–tdEos; e, f, vinculin–tdEos; g, h, zyxin–mEos2; i, j, VASP–mEos2; k, l, α-actinin–mEos2. The vertical distribution of α-actinin is non-Gaussian, so the focal adhesion peak fit is not shown. Paxillin and α-actinin shown are C-terminal PA-FP-tagged (N-terminal fusions in Supplementary Figs and ). Colours: vertical (z) coordinate relative to the substrate (z=0nm, red). Scale bars: 5 μm (a, c, e, g, i, k) and 500 nm (b, d, f, h, j, l).