FIG. 1.

Comparison of anti-Vi IgG standard curves using the ELISA or bead assay. A human serum standard (pooled) containing anti-Vi IgG (200 ELISA units/ml in undiluted serum) was tested over various dilutions by ELISA or bead assay, and the raw data values from each assay platform were plotted against the anti-Vi IgG EU/ml in the diluted serum. The average values for sample diluent controls included in each assay are indicated. The results shown in Fig. 1 represent a total of 32 standard curves generated using ELISA and 46 standard curves generated using the bead assay.