Interpretation of fluorescence photobleaching recovery experiments on oriented cell membranes.

Both quantitative and qualitative aspects of the interpretation of fluorescence photobleaching recovery experiments as typically practised to obtain information on lateral diffusion processes in cell membranes are called into question in view of the polarized nature of the laser light sources routinely employed. Protocols which will eliminate the effects elicited under these conditions by any concurrent slow rotational diffusion are delineated.