TABLE 2.

Global Intensity Decay Analysis of LysoSensor Probes^a

LysoSensor	pH	α1b	α2b	α3b	f1b	f2b	f3b	〈τ〉
DND-167	4.2	1.000	0.000	0.000	1.000	0.000	0.000	11.4
	5.7	0.651	0.215	0.134	0.894	0.100	0.006	10.6
	6.3	0.436	0.304	0.260	0.797	0.189	0.014	9.8
	6.9	0.144	0.471	0.385	0.457	0.508	0.035	7.2
τ1 = 11.4 ns, τ2 = 3.9 ns, τ3 = 0.3 ns, ${\chi }_{\text{R}}^2$ = 7.2c
DND-153	4.3	1.000	0.000		1.000	0.000		6.4
	7.5	0.838	0.162		0.979	0.021		6.2
	8.2	0.588	0.412		0.927	0.073		5.9
	8.8	0.329	0.671		0.814	0.186		5.3
	9.4	0.106	0.894		0.515	0.485		3.6
τ1 = 6.4 ns, τ2 = 0.7 ns, ${\chi }_{\text{R}}^2$ = 6.4c
DND-189	3.1	0.000	1.000	0.000	0.000	1.000	0.000	4.1
	3.7	0.577	0.422	0.001	0.651	0.349	0.000	5.1
	4.1	0.857	0.126	0.017	0.898	0.096	0.006	5.4
	4.4	0.990	0.009	0.001	0.993	0.007	0.000	5.6
	5.2	0.999	0.000	0.001	1.000	0.000	0.000	5.6
	5.7	0.908	0.000	0.092	0.968	0.000	0.032	5.5
	6.8	0.509	0.000	0.491	0.758	0.000	0.242	4.7
τ1 = 5.6 ns, τ2 = 4.1 ns, τ3 = 1.8 ns, ${\chi }_{\text{R}}^2$ = 7.0c
DND-189	5.2	0.970	0.030	0.000	0.996	0.004	0.000	6.4
	5.7	0.537	0.142	0.321	0.679	0.024	0.297	5.8
	6.1	0.141	0.365	0.494	0.256	0.089	0.655	4.8
	6.5	0.076	0.546	0.378	0.179	0.173	0.648	4.4
	6.8	0.048	0.706	0.246	0.149	0.295	0.556	3.8
	7.2	0.013	0.864	0.123	0.059	0.532	0.409	2.8
	7.5	0.000	0.903	0.097	0.000	0.632	0.368	2.3
τ1 = 6.4 ns, τ2 = 0.9 ns, τ3 = 4.7 ns, ${\chi }_{\text{R}}^2$c
DND-160d	2.2	1.000	0.000		1.000	0.000		2.4
	2.7	0.871	0.129		0.956	0.044		2.3
	3.0	0.627	0.373		0.846	0.154		2.1
	3.7	0.356	0.644		0.643	0.357		1.8
	4.3	0.167	0.833		0.395	0.605		1.4
	6.1	0.112	0.888		0.291	0.709		1.2
τ1 = 2.4 ns, τ2 = 0.7 ns, ${\chi }_{\text{R}}^2$ = 2.3c

^aThe average lifetime of LysoSensor DND-192 (λ_ex = 365 nm, λ_em = 450 ± 20 nm) is 12 ns at either acidic (pH 4.3) or basic (pH 8.8) buffers.

^bThe amplitudes and fractional intensities are normalized to unity.

^cThe accuracies of phase angle and modulation for the instrumentation were 0.3° and 0.008, respectively.

^dThe average lifetimes of LysoSensor DND-160 (λ_ex = 350 nm, λ_em = 535 ± 25 nm) is 2.37 ns at either acidic (pH 3.0) or basic (pH 8.1) buffers.