Fig. 4. Number of cells showing blocked dye diffusion at the leading edge (single peak intensity scan) under different labelling conditions. (a) CA treatment reduced the fraction of single peak cells from 86% (n=138) to 51% (n=45). CA/CB treatment further reduced this value to 4% (n=49). (b) The diffusion of carbocyanine dyes that have different acyl chain lengths was equally inhibited during protrusion at the leading edge. Extraction of 35% of cholesterol by CD treatment marginally reduced the fraction of single peak cells from 86% to 75% (n=36).