Fig. 2A–C .

Validation of the multiplex Luminex assays by comparison with single antigen assays is shown. (A) This graph shows a comparison of single-antigen and multiplex Luminex immunoassays. Each of the 14 recombinant proteins was coupled to its assigned LumAvidin™ beads and incubated with a single patient serum at the indicated dilutions either individually (singleplex), or together with the other 13 antigens (multiplex). After a wash step, the secondary antibody, phycoerythrin-conjugated goat-anti-human immunoglobulin (IgG), was added and the fluorescence intensities were measured. Representative data for IsdB are shown. The interclass correlation (ICC) of singleplex versus multiplex assays was measured. (B) Data were generated for the other 13 antigens in single- and multiplex formats, and measured values for all eight dilutions of all 14 antigens were compiled. (C) The ELISA compared with Luminex immunoassay data are shown. The diagonal line in Illustrations B and C represents the formula of y = x.