Fig. 1.
Current of molecules arriving at the specific binding site, as a function of τres. The number of molecules arriving per second is calculated according to (22); NT = 200, n = 66,000 nm (corresponding to 50,000 binding sites of 1.32 nm each), τ3D = 0.04, 0.06, 0.1, 0.12, 0.14 ms (a) or τ3D = 0.1 ms (b), D = 30 nm2/ms (a) or D = 30,40,60,70,80 nm2/ms (b). τ3D, D and τres were approximated according to [16]. The two limits of short and long residence times correspond to pure 3D and pure 1D diffusion, respectively. Combined 3D + 1D diffusion produces a peak at τres = τ3D