Table 3.

Emission wavelength-dependent intensity decays of Fura-2^a.

λobs (nm)	Free anion (no Ca2+)c τ1 = 0.21 ns, τ2 = 1.15 ns		Ca2+-bound (40 μM Ca2+) τ1 = 0.16 ns, τ2 = 1.78 ns
	α1	f1	α1	f1
460b	0.464	0.134	0.494	0.080
500	0.347	0.086	0.189	0.021
540	0.292	0.068	0.114	0.012
580	0.161	0.033	−0.138	−0.014
600	0.088	0.013	−0.225	−0.026

^aExcitation wavelength was 354 nm, T = 20°C.

^bWith bandpass of 10 nm.

^cGlobal fits for free anion and Ca²⁺ bound forms. For these two global fits we used |α₁| + α₂ = 1 and f₁ + f₂ = 1.0, respectively.