Figure 1.
Mobility of mGFP–hDAT at the live cell plasma membrane. A, to determine the mobile fraction of mGFP–hDAT, FRAP experiments were performed on cells expressing mGFP–hDAT. The integrated intensity of the bleached area (I) was normalized to the fluorescence intensity before bleaching (I0) and plotted over time (black circles, showing a representative recovery curve). The average over 11 cells yielded a mean mobile fraction of m = 78 ± 10%. B, using single molecule tracking, the diffusion coefficient D was determined. Mean square displacements were calculated for a range of time lags (t-lag) and D was determined from the first two points in the MSD plot according to MSD = 4Dtlag + offset, yielding D = 0.118 ± 0.002 μm2/s. Error bars show the mean ± S.E.