Figure 1.

(a) Orientational freedom of a single fluorescent probe in a membrane. (b) Space- and time-averaging in an ensemble of probes are described by a 3D distribution, f(θ,φ), of single dipoles oriented with angles (θ,φ), as probed by the electric field. (c) Corresponding 2D effective angular distribution, p(φ), given by Eq. 4. (d) A single fluorescent dipole linked to a membrane protein with a given angular constraint in the membrane. (e) Corresponding ensemble averaging orientation in a 3D distribution. (f) 2D effective distribution. To see this figure in color, go online.