TABLE 2.

IsdB serologic assay summary

Assay characteristicLimit(s)
EXV limitaRange of absolute MFI of >10 and of transformed MFI of >0.22
LOD (non-dilution corrected, ng/ml)0.425 ng/ml
LOD (dilution corrected, μg/ml)1.06
LOQs (non-dilution corrected, ng/ml)0.85-425
LOQs (dilution corrected, μg/ml)2.1-10,625
RMSE upper limit (MFI)2σ limit, ≤0.30; 3σ limit, ≤0.36
Slope limits (MFI/ng/ml)2σ limit, 0.70, 0.83; 3σ limit, 0.67, 0.86
EC50 limits (ng/ml)2σ limit, 112, 362; 3σ limit, 83, 486
Control 1 limits (μg/ml)2σ limit, 191, 335; 3σ limit, 166, 385
Control 2 limits (μg/ml)2σ limit, 70, 123; 3σ limit, 61, 141
Control 3 limits (μg/ml)2σ limit, 23, 40; 3σ limit, 20, 46
Control 4 limits (μg/ml)2σ limit, ≤3.2; 3σ limit, ≤3.7
Intra-assay precision (% RSD)8.0%
Interassay precision (% RSD)14.2%
Total precision (% RSD)16.6%
Assay ruggedness (% difference between
    conditions)−6.8% to 3.0%
Dilutability (% bias per 10-fold dilutions
    between 1:2,500 and 1:25,000)−4.1%
Dilutability (% bias per 10-fold dilution
    between 1:100 and 1:102,400)−13.0%
Specificity to IsdB97.8%
  • a Limits for untransformed and fifth root-transformed MFIs.