Fig. 2.

Results obtained on diluted individual milk samples. On the x-axis, 1 corresponds to the undiluted sample, while 2-8 represent dilution steps 1/2 up to 1/128. □ = mean bl% using the Danish blocking ELISA; ∆ = mean PP-value using the SVANOVIR. Grey bars represent 95 % confidence interval around each mean, H: highly positive group (n = 4), M: medium positive group (n = 3), and L: low positive group (n = 3). Horizontal dashed lines represent the cut-offs (bl% = 0 and PP = 2), above which samples were classified as antibody positive. N.B. Test values below zero do not have any biological meaning, and thus, in the 95 % confidence intervals we set the minimum bar limit to 0. We proceeded in a similar way for the maximum limit of the blocking ELISA, which cannot have values > 100 %