Results of the multiplex infectious-antigen array (MIAA) assay for the 3 patients with an hepatitis C virus–specific (HCV-specific) monoclonal (mc) IgG. For each patient, the results obtained for HCV core, NS-3, or NS-4 proteins with the patient’s serum and purified mc IgG are shown. Serum contained IgG that recognized the HCV core (P205, P206, P207) and NS-3 (P206) or NS-4 (P205, P207), whereas the purified mc IgG recognized only the HCV core (P205, P206) or NS4 (P207). The fluorescence values shown for each HCV protein were obtained after subtraction of the threshold of specific positivity (500 for HCV). Dots may be superimposed; horizontal bars represent means of results obtained for HCV core, NS3, or NS4. Experiments were performed at least twice.