Fig. 4.

Antibody reactivity in the MBio assay for 181 clinical samples with known HCV antibody serostatus (60 positive and 121 negative). Spot intensity is the background-subtracted, normalized intensity described in the text. Antibody reactivity against all antigens is measured simultaneously for each sample. Box plot details are as described in the legend to Fig. 3. The dashed lines are empirically derived cutoffs for the core and NS3 recombinant antigens. The synthetic NS4* and Multi** multiple-epitope antigens showed relatively high signals on the HCV Ab negative samples, so cutoffs for these two antigens were not used in subsequent analyses.