TABLE 2.

Static anisotropies

	R‖	R⊥
Rigor (Rh-phalloidin)*	0.333 ± 0.018†	−0.026 ± 0.043
Relax (Rh-phalloidin)	0.272 ± 0.014	0.122 ± 0.026
Rigor (Alexa-ATP)‡	0.144 ± 0.014	0.119 ± 0.008
Relax (Alexa-ATP)	0.152 ± 0.017	0.091 ± 0.013

The anisotropies were measured in a wide-field microscope using 10× (NA = 0.22) objective. They are defined as: R_⊥ = (_⊥I_⊥/C_⊥ − _⊥I_‖)/(_⊥I_⊥/C_⊥ + 2_⊥I_‖), and R_‖= (_‖I_‖/C_‖ − _‖I_‖)/(_‖I_‖/C_‖ + 2_‖I_⊥), where the Cs are correction factors accounting for depolarization of light by microscope optics. The fiber, not the polarization of exciting light, was rotated by 90° to make C_⊥ = C_‖. Using Chroma rhodamine and Cy5 dichroic mirrors, C = 1.1 and 0.98, respectively. The anisotropy R is related to the polarization of fluorescence P by R = 2P/(3–P).

^*Rh-phalloidin on actin.

^†Mean ± SE, n = 5.

^‡Alexa647-ATP on actin. Excitation at 633 nm.