Detection and characterization of membrane microheterogeneity by resonanceenergy transfer

The application of resonance energy transfer (RET) in the study of heteroge neity in membrane systems is described. Useful formalisms for monophasic an d biphasic systems are presented, together with quantitative studies. Evide nce for reduction of dimensionality, probe segregation, and microdomain siz es in these systems is discussed. Selected examples of multicomponent syste ms (natural membranes or model systems including proteins) are also referre d, as well as recent work using RET under the microscope.