FRAP: Fluorescence Recovery After Photobleaching
What it does best:
Recovery of fluorescence in a defined region of a sample after a bleaching process. Results from the movement of unbleached fluorophores from the surrounding area into the bleached region. Fluorophores in a selected region of the cell are bleached using laser light to make them inactive. Any return of fluorescence to the “bleached” area over time is due to the diffusion or transport of molecules incorporating unbleached fluorophores. Technique can be used to measure molecular dynamics.
What it can’t do:
Examples of uses:
Used to measure the dynamics of 2D or 3D molecular mobility example: in diffusion, transport or any other kind of movement of fluorescence-labeled molecules in membranes or living cells. Used to image and measure rates of intracellular molecular dynamics. Example: used to image microtubule and cytoskeletal dynamics and mobility of membrane proteins. Useful tool in understanding protein dynamics in living cells. Can be used to assess receptor motility, study signaling events and determine the continuity of membranes such as the endoplasmic reticulum.