Table 1.

Spectral and Reactivity Properties of Dyes in PBS (pH 7.4).^[a]

	756z	s775z	UL766[g]	ZW800–1[g]	CW800[g]
λabsmax (nm)	681 (a)[f] 756 (m)[f]	775	766	770	775
λemmax (nm)	773	794	789	788	796
ε (M−1cm−1) (R2)[b]	99,000 (0.942)[b]	201,000 (0.999)	229,000	246,000	242,000
QY[c]	0.097	0.090	0.095	0.135	0.090
Brightness[d]	9,600	18,000	22,000	33,000	22,000
Stable to nucleophiles[e]	Yes	Yes	Yes	No	No

^[a]Concentration range of dyes is 0 – 5 μM. All measurements were made at room temperature.

^[b]Molar absorptivity of monomer band, nonlinear relationship with concentration due to dye self-aggregation.

^[c]Quantum yield relative to UL766, error is ±10%.

^[d]ε x QY, error is ±15%.

^[e]Meso linkage is not cleaved by biological amines or thiols.^[10,12]

^[f]a = aggregate; m = monomer.

^[g]Spectral data from reference.^[10,23]