Characteristics of the sero-MAP based multiplex assay measuring autoAb plus PSA. (A). seroMAP and ELISA were compared for measuring autoAb against the prototype NY-ESO-1:1-40 peptide and the XAGE-1b:1-25 peptide. Specific MFI ratios (or OD) from randomly selected seropositive patients were divided by the mean of 8 HD to represent signal-to-noise ratios of the seroMAP and ELISA approach. (B). MFI ratios of autoAb against NY-ESO-1:1-40 versus a control obtained by the multiplex A+PSA and the singular assay had a correlation coefficient of 0.98 (n = 40), where the linear equation for NY-ESO-1 autoAb is A+PSA = 0.86*singular NY-ESO-1 + 0.20. (C). Comparison of seroMAP-based A+PSA and classic ELISA for determining total PSA values (ng/ml) using serum samples of randomly selected 376 subjects. The three fitted linear regressions for 1:10, 1:20, and 1:50 dilution were A+PSA = 0.89*PSA+0.15, A+PSA = 0.90*PSA+0.30, and A+PSA = 0.90*PSA+0.43, respectively. Methods of determining PSA levels using seroMAP-based A+PSA and classic ELISA (American Qualex) were described in "Materials and Methods".