Figure 3.

Diagnostics performance of the Nanobody (Nb94) based 3ABC competitive ELISA. (A) Receiver-Operating Characteristic (ROC) analysis results from a total of 222 cattle sera. Dotted lines represent 95 % confidence interval. (B). Lower limit of detection (LLD) using positive (infected sera) and negative (noninfected sera) control serum. Cutoff assay is indicated by dash line. (C) Intra assay repeatability performance was assessed using a set of positive and negative internal control sera tested in the assays in different days and by different operators. Lower and upper limits (2 × STDV) are indicated by dot lines. Cutoff assay is indicated by dash line. The total average and STDV of positive and negative internal control sera across the different experiments is also presented. Statistical analysis: ^*P < 0.05, ^**P < 0.01, ^***P < 0.001.