Table 1.

Experimental steady-state anisotropy values and time-resolved anisotropy decay parameters

A*	Free Cy3	Free Cy5	EGFCy3	EGFCy5	EGFFluorescein
PBS	0.230	0.194	0.271	0.210	0.077
99% Glycerol			0.382	0.388	0.313‡
B†	β1	φ1	β2	φ2	r∞
EGFFluorescein	0.20	0.11	0.06	4.58	0.04

The measurement errors are ∼1%.

^*Experimental steady-state anisotropy values for free fluorophores and EGF derivatives in solution used to calculate the errors in FRET-derived inter-EGF distances.

^†Time-resolved anisotropy decay parameters of EGF^Fluorescein in PBS.

^‡Excited away from absorption maximum at 445 nm.