Figure 1

Figure 1

Analysis of the time stack of images acquired for 5 min (5 s time steps) after the injection of very concentrated rhodamine in solidified agarose. (a) One frame acquired a few seconds after injection. The dashed blue hemi-circle indicates the cross-section of the needle for injection. The red rectangle represents one of the ROIs over which the intensity profile was measured versus time at different distances from the injection point. (b–d) Intensity profiles measured on ROIs at increasing distance from the injection point (in the legend), as described in the legend, from samples at different agarose concentrations (1, 2 and 5%, respectively), together with their best fit to Equation (4) (continuous line).