TABLE 1

Characterization of Imaging Conjugates

mAb	k_a (M⁻¹ s⁻¹)	k_d (s⁻¹)	Fab equilibrium affinity constant (K_D = k_d/k_a) (nM)	No. of DOTA/protein	No. of IRDye800/protein	Percentage biologic activity
9601	2.6 × 10⁵	4.0 × 10⁻³	15.4	3.0 (1.0)	2.3 (0.5)	79.5 (0.8)
153	2.2 × 10⁵	1.2 × 10⁻⁴	0.54	4.6 (1.1)	2.1 (0.5)	81.8 (1.5)
7	4.3 × 10⁵	9.9 × 10⁻⁴	2.3	5.1	2.3	86.4 (1.8)^*
69	Not applicable^†	Not applicable	Not applicable	4.2 (2.6)	3.4 (0.4)	3.2 (0.3)^‡

↵* P < 0.05 for mAb 7 vs. 9601 and 153.
↵† Not applicable because mAb 69 is isotype control targeting pili.
↵‡ P < 0.05 for IgG₁ isotype control mAb 69 vs. mAb 7 and 153 and for commercial IgG_2b isotype control (0.7% ± 0.1%, data not shown in Table 1) vs. mAb 9601.
Data in parentheses are SDs.