Figure 2.

Measurement of GFP diffusion coefficient in the nucleoplasm and the nucleolus. Each measurement is performed on an individual cell (a), scanning the beams across the nucleolus (b). The GFP intensity trace is used for sorting the ACFs between the nucleolus (in blue) and the nucleoplasm (in red) (c). The total ACF without sorting (d) is compared to the sorted ACFs calculated from the fluctuations measured in the two regions (e and f). (g) The average values of diffusion coefficient of GFP in the nucleolus (nl) and nucleoplasm (np) was extracted from the fitting of the sorted ACFs (mean ± SD of n = 73 cells from five independent experiments). (h) Scatter plot of D_nl versus the value of D_np measured on the same cell is shown. Data represent measurements from different cells in a representative experiment. The solid black line is a linear fit with the intercept fixed to zero and slope 0.54 ± 0.04. The dashed red line represents the case in which the diffusion coefficients are the same in both the compartments. To see this figure in color, go online.