Table 3.

Precision of dried blood spot serology results from a multiplex bead assay

	Eluate 1 vs. Eluate 2 (Run A vs. Run B)			100 beads vs. 50 beads (Run B vs. Run C)
Antigen	Mean difference	95% LOA	ICC	Mean difference	95% LOA	ICC
pgp3	−204.3	(–3,405.3, 2,996.7)	0.990	167.5	(–2,009.9, 2,344.9)	0.995
CT694	−339.8	(–2,896.3, 2,216.6)	0.979	44.0	(–1,043.3, 1,131.2)	0.996
CTB	−124.3	(–1,322.7, 1,074.0)	0.968	20.2	(–445.8, 486.3)	0.995
ETEC LTB	−225.2	(–1,613.2, 1,162.8)	0.972	34.1	(–513.8, 582.0)	0.995
Cp17	−643.6	(–4,521.6, 3,234.5)	0.981	320.2	(–2,246.6, 2,886.9)	0.992
Cp23	−690.6	(–4,691.2, 3,309.9)	0.970	324.1	(–1,845.4, 2,493.6)	0.991
LecA	−134.1	(–1,124.0, 855.8)	0.977	9.9	(–393.0, 412.8)	0.996
p18	−177.3	(–1,460.2, 1,105.7)	0.978	9.9	(–526.3, 546.0)	0.996
p39	−434.0	(–3,840.9, 2,973.0)	0.958	220.4	(–1,612.0, 2,052.9)	0.987
Sal B	−101.0	(–1,700.4, 1,498.3)	0.850	40.8	(–584.6, 666.2)	0.967
Sal D	−36.8	(–850.0, 776.3)	0.907	9.0	(–242.2, 260.3)	0.988
VSP3	−252.5	(–2,153.2, 1,648.2)	0.981	82.2	(–1,002.4, 1,166.7)	0.994
VSP5	−274.7	(–2,241.5, 1,692.1)	0.983	101.5	(–1,083.1, 1,286.1)	0.994

ICC = intraclass correlation coefficient; LOA = limits of agreement. Values represent pairwise comparisons of raw median fluorescence intensity minus background values from 392 children. Eluate 1 was taken from the first blood spot extension and eluate 2 from the second blood spot extension. The bead comparison (e.g., 50 vs. 100) refers to the number of bead reads per well used by the software algorithm.