Arp2/3 complex patches in filopodia are highly dynamic and co-localise with increases in RFP actin signal. Cells were spread for 60 minutes on fibronectin after co-transfection with GFP p21-arc and RFP actin. Solid arrows indicate Arp2/3 complex foci in filopodia and hollow arrows indicate the corresponding location in the RFP actin images. Images are taken from Movie 4. Scale bar 10 μm.