Final answer:
The method described in the question is called Fluorescence Recovery After Photobleaching (FRAP). It is used to estimate the relative mobility of molecules on the surface of a living cell.
Step-by-step explanation:
The method described in the question is called Fluorescence Recovery After Photobleaching (FRAP). FRAP is a technique used to estimate the relative mobility of molecules on the surface of a living cell. In this method, molecules of interest are fluorescently labeled, and a small area of the label is bleached. The speed of signal recovery is then measured as the molecules migrate back into the bleached area.