Figure 1. Signal-to-noise ratio performance assessment strategy for mAbs.

The strategy to assess the performance of each mAb in the PCD panel relies on defining a negatively and positively staining population for each mAb. These populations are defined in Table 3. Next, the median fluorescence intensity (MFI) is determined for each population and the signal-to-noise ratio calculated by dividing the positive population’s MFI by the negative population’s MFI. To qualify as an acceptable mAb, the calculated signal-to-noise value should be greater than the recommend value in Table 4. Panel 1A: For CD45, erythroid precursors are used as the negative population defined as SSC^lo/CD45⁻ events (r1: yellow dots and corresponding histogram) and T cells as the positive population defined as CD45^br/SSC^lo (r2) and CD19⁻/CD56⁻ events (r3: black dots and corresponding histogram). Panel 1B: For CD19, NK cells are used as the negative population defined as CD45^br/CD56⁺ events (r4: yellow dots and corresponding histogram) and B cells as the positive population defined as CD19+/CD45^br events (r5: black dots and corresponding histogram). Panel 1C: For cKappa light chain, cLambda light chain⁺ B cells are used as the negative population defined as CD45^br/SSC-A^lo (r6) and CD19⁺/cLambda light chain⁺ events (r7: yellow dots and corresponding histogram) and cLambda light chain⁻ cells as the positive population defined as CD45^br/SSC-A^lo (r6) and CD19⁺/cLambda light chain⁻ events (r8: black dots and corresponding histogram). Panel 1D: For CD138 a procedural control for immunophenotyping, CD-Chex CD103™ Plus cells which contains a CD138 positive population are spiked into a bone marrow sample. B cells are used as the negative population defined as CD45^br/CD19⁺ events (r9: yellow dots and corresponding histogram) and spiked control cells as the positive population defined by FSC-A and SSC-A (r10) and as CD45^dim/CD81⁺ events (r11: black dots and corresponding histogram). Note these data are all gated on R1 & R2 & R3, ‘Total Leukocytes’ as defined in Fig. 2. In data not shown, for the CD19 negative and positive populations, and CD138 negative population a FSC-A vs SSC-A plot was used to define lymphocytes.