eBook: Multiplex Technology Guide - 18

Figure 3. Correlation analysis of concentrations of the 16 cytokines measured in human plasma samples by the Luminex (LMX) and Meso
Scale Discovery (MSD) multiplex assays. Bland-Altman plots were used to assess agreement between the two platforms. Log2 values of
the MSD/LMX concentration ratios are shown on the y-axis and provide a visual assessment of estimates of systematic differences in
measurement between methods when the mean value deviates from 0. In this presentation, a negative shift in the mean indicates that
the MSD assay classifies the analyte as concentrations lower than LMX, and vice versa. Mean analyte concentrations (in pg/mL) are
shown on the logarithmic x-axis, and precise values appear above the dotted horizontal " mean " lines in each graph. The ±1.96 SD lines
represent the 95% limits of agreement, and when SDs are large or n-values are low, interpretation can be ambiguous. For most shared
analytes, the mean is shifted to a negative value, indicating that the MSD assay quantified an analyte at a lower concentration than the
LMX assay in the same samples. Exceptions appear to be MIP-1α and MIP-1β, where the LMX assay, on average, characterized samples at
lower concentrations than the MSD assay.

MSD 10-plex assays in the 96-well format was 20
hours and 28 minutes and 21 hours and 33 minutes
for the LMX and MSD assays, respectively, including

an overnight incubation (Figure 5). The average
hands-on labor/vigilant observation time was 1 hour
and 37 minutes for LMX and 2 hours and 33 minutes

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