Arp2/3 complex and vinculin in filopodia. A. MEF spread on fibronectin for 60 minutes. Labelling for vinculin showed numerous focal adhesions. Scale bar 20 μm. B. Enlargements of boxed areas in A. Vinculin labelling of filopodia is variable in intensity and not comparable to Arp2/3 complex labelling. Scale bar 5 μm. C. vinculin null MEF spread on fibronectin for 60 minutes. Labelling with vinculin antibody shows complete loss of vinculin labelling. Actin was labelled with rhodamine phalloidin and Arp2/3 complex with an antibody to the p34-Arc subunit. Scale bar 20 μm. D. Enlargements of boxed areas in A. Scale bar 5 μm.