Table 1.

Comparison between avidity indices determined by ELISA using a multiple diluted serum with a single concentration of a chaotrope calculated according formula of Perciani et al. 21 (area 6 mol/L or area 8 mol/L) and our modified method included only serum dilution 1:50 and 1:100 (area 6 mol/L modified or area 8 mol/L modified)

Comparison urea as chaotrope	n	r	P	Comparison NaCl as chaotrope	n	r	P
Area 6 mol/L vs area 8 mol/L	18	.95	<.0001	Area 1 mol/L vs area 2 mol/L	20	.93	<.0001
Area 6 mol/L vs area 6 mol/L modified	18	.96	<.0001	Area 1 mol/L vs area 1 mol/L modified	20	.92	<.0001
Area 8 mol/L vs area 8 mol/L modified	18	.98	<.0001	Area 2 mol/L vs area 2 mol/L modified	20	.92	<.0001
Area 6 mol/L modified vs area 8 mol/L modified	24	.95	<.0001	Area 1 mol/L modified vs area 2 mol/L modified	20	.89	<.0001

n, number of samples; r, Pearson's correlation coefficient; P, level of significance; vs, versus.