Figure 5
STED-FCS of lipid diffusion in different parts of the cell and in PtK2 cells.
(a) Dapp(d) dependencies in NRK cells: diffusion near the cell edge (lamellipodia) and under the cell body (as labelled). (b) Values of Dapp for confocal (d = 240 nm, filled columns) and STED recordings (d ~ 40 nm, open columns) for diffusion probed near the cell edge (control, blue) and under the cell body (purple) – the increase in Dapp from 240 to 40 nm indicates the extent of compartmentalised diffusion. Compartmentalised diffusion is more pronounced near the cell edge. (c) Results from measurements on PtK2 cells: Experimental diffusion coefficient of the fluorescent DPPE analogue in the plasma membrane of untreated and CK-666-treated PtK2 cells (d = 240 nm). We have previously shown5,23 that diffusion of this DPPE analogue in PtK2 cells is apparently free, therefore the measurements corresponding to d = 240 nm are expected to effectively represent the range (d = 40 nm to d = 240 nm). Error bars are s.e.m. Symbols on top of the columns represent results of the statistical test (**P < 0.01, *P < 0.05, NS not significant; two-tailed unpaired t test): for d ~ 40 nm comparison with the value representing d = 240 nm in the same experiment and for d = 240 nm comparison with the respective value for d = 240 nm in the control experiment. Here, n stands for the number of cells, from r samples.
