TABLE 3.

 Influence of ELISA blocking solutions on control samples^a

Reagent	Mean OD
	Control 1	Control 2	Control 3	Control 4	Control 5	Control 6	Control 7	Control 8	Control 9	Control 10
Milk	0.000	0.000	0.006	0.000	0.008	0.000	0.000	0.000	0.000	0.000
Milk + Tween 20	0.024	0.006	0.018	0.003	0.008	0.001	0.004	0.004	0.012	0.070
BSA	0.055	0.012	0.026	0.003	0.032	0.010	0.012	0.006	0.061	0.018
BSA + Tween 20	0.088	0.019	0.088	0.124	0.064	0.166	0.054	0.038	0.12	0.021
Tween	0.095	0.070	0.061	0.030	0.068	0.028	0.061	0.069	0.065	0.057
PVA-50	0.032	0.018	0.026	0.012	0.032	0.000	0.000	0.000	0.011	0.028
PVA-50 + Tween 20	0.042	0.007	0.014	0.003	0.012	0.007	0.008	0.008	0.027	0.020

^aControl samples were obtained from HPV DNA-negative virginal women (25). A two-way analysis of variance was used to assess the statistical significance between the average ODs obtained with different blocking solutions (P < 0.0001). Milk and BSA were added to the blocking solutions at final concentrations of 5% each, Tween 20 was added at a final concentration of 0.05%, and PVA-50 was added at a final concentration of 0.5%. Values represent the mean OD for each sample run twice.