Fig. 3
Determination of the cut-off value, specificity, and sensitivity of the indirect ELISA assay. (a) 32 antisera samples from chicken not exposed to S. Pullorum were subjected to the indirect ELISA assay to obtain the cut-off value. (b) Antisera samples from chicken infected with other Salmonella serotypes or avian bacteria (E. coli and Campylobacter jejuni) were used to determine the specificity of the indirect ELISA assay. All of the OD450nm values of these antisera samples were below 0.4. (c) Positive antisera against S. Pullorum were serially diluted from 1:100 to 1:12800, and then used to identify the sensitivity of the indirect ELISA assay (**: p < 0.01)
