Table 3 Summary of validation parameters for Tier 1 and Tier 3 assays. CI: confidence interval. CV: coefficient of variation. Source data are provided as a Source Data file.
Validation parameter | Results | |
|---|---|---|
Tier 1 | Tier 3 | |
Method comparison n Tier 1 = 445 samples n Tier 3 = 540 samples | Accuracy = 87.2% (CI 95%, 83.8–90.0%) Sensitivity = 78.2% (CI 95%, 72.4–83.0%) Specificity = 96.8% (CI 95%, 93.5–98.4%) | Accuracy = 87.7% (CI 95%, 79.4–95.2%) Sensitivity = 83.6% (CI 95%, 70.6–95.7%) Specificity = 93.3% (CI 95%, 82.4–100%) |
Linearity n = 12, 4 levels | IGMEVTPSGTWLTYTGAIK: up to 1000 ng/mL R2 = 0.9948, mean recovery = 101.2% DGIIWVATEGALNTPK: up to 1000 ng/mL R2 = 0.9786, mean recovery = 103.6% | Not applicable |
Limits of blank n Tier 1 = 52 n Tier 3 = 38 | IGMEVTPSGTWLTYTGAIK: relative response factor = 0.068 DGIIWVATEGALNTPK: relative response factor = 0.101 | IGMEVTPSGTWLTYTGAIK: Signal-to-noise = 1.65 DGIIWVATEGALNTPK: Signal-to-noise = 0.83 |
Limits of detection n Tier 1 = 50 n Tier 3 = 20 | IGMEVTPSGTWLTYTGAIK: relative response factor = 0.117 (equivalent to 2.7 ng/mL) DGIIWVATEGALNTPK: relative response factor = 0.162 (equivalent to 3.2 ng/mL) | IGMEVTPSGTWLTYTGAIK: Signal-to-noise = 3.03 DGIIWVATEGALNTPK: Signal-to-noise = 1.10 |
Limits of quantification n = 45 (5 levels, 9 independent replicates) | IGMEVTPSGTWLTYTGAIK = 6.0 ng/mL DGIIWVATEGALNTPK = 4.4 ng/mL | Not applicable |
Reproducibility n Tier 1 = 44 n Tier 3 = 10 | Negative: undetectable Positive (mean = 21.9 ng/mL): IGMEVTPSGTWLTYTGAIK: CV = 17.5% DGIIWVATEGALNTPK: CV = 19.2% | Negative: undetectable Positive: IGMEVTPSGTWLTYTGAIK: CV = 19.8% DGIIWVATEGALNTPK: CV = 18.7% |
Carryover n = 12 | IGMEVTPSGTWLTYTGAIK: 1.2% and 0.2% (first and second injection) DGIIWVATEGALNTPK: 4.0% and 0.7% (first and second injection) | |
Stability n = 299 (5 replicates per condition), 95% CI | Sample storage stability: Saline: stable for all conditions (30 days, 21 oC, 4 oC, −20 oC and −80 oC) Virus transport medium: p < 0.05 at 21 oC to low viral load for all storage time Thermal test (90 oC for 5 min): Stable for all conditions | |
Interference | Undetected (Supplementary Table 5) | |
