The localisation of the Arp2/3 complex in spreading mouse embryonic fibrobloasts. MEFs were plated onto fibronectin and fixed at 5, 15, 30 and 60 minutes. Actin was labelled with rhodamine phalloidin and Arp2/3 complex with an antibody to the p34-Arc subunit. Boxed areas are enlarged in B. Scale bar 10 μm.