Mobile fraction is typically measured using the FRAP technique. In FRAP, a specific region of a cell containing fluorescently tagged molecules is bleached using a high-intensity laser. Over time, the movement of unbleached fluorescent molecules into the bleached area is monitored to assess the recovery of fluorescence. The mobile fraction is calculated by comparing the intensity of fluorescence before bleaching and after recovery. This method provides quantitative data on the mobility and diffusion rates of molecules within cells.
