Table 2.
Results Validation ADx Nf-L ELISA.
| Parameter | Acceptance Criteria | ADx | AUMC | ||||
|---|---|---|---|---|---|---|---|
| Sensitivity—LLOQ Conc | Meanblank + 10 × SDblank | 148 | 348 | ||||
|
Spike-Recovery Low spike Medium spike High spike |
80–120% recovery | Conc (recovery %) | Conc (recovery %) | ||||
| 283.1 (54–85%) | 665 (100–131%) | ||||||
| 867.8 (61–96%) | 3508 (100–106%) | ||||||
| 5231.2 (76–98%) | 15,710 (94–99%) | ||||||
|
Precision Low sample Medium sample High sample |
CV < 20% | Conc. | Intra-assay | Inter-assay | Conc. | Intra-assay | Inter-assay |
| 165 | 10.6% | 15.4% | 450 | 24.9% | 24.9% | ||
| 487 | 4.3% | 4.3% | 2514 | 3.9% | 8.3% | ||
| 1316 | 3.8% | 3.8% | 14,420 | 2.9% | 10.7% | ||
| Mean | 6.2% | 7.8% | Mean | 10.5% | 14.6% | ||
| Dilutional Linearity | 80–120% linearity | Mean 3 samples | Mean 3 samples | ||||
| DF (x) | %L | DF (x) | %L | ||||
| 1 | - | 1 | - | ||||
| 3 | 105 | 5 | - | ||||
| 9 | 106 | 25 | 118 | ||||
| 27 | 137 | 125 | 114 | ||||
| 81 | 127 | 625 | 97 | ||||
| 243 | 74 | 3125 | 106 | ||||
| Mean | 110% | Mean | 109% | ||||
|
Parallelism R2 Slope Range |
80–120% in range with the slope of the calibrator | Mean 5 samples | Mean 5 samples | ||||
| Mean | SD | Mean | SD | ||||
| 0.993 | 0.006 | 0.986 | 0.012 | ||||
| 0.795 | 0.030 | 0.703 | 0.105 | ||||
| 90% | 3% | 93% | 14% | ||||
All concentration values are in pg/mL. The table shows the LLOQ of the ELISA, the mean spike-recovery for three different CSF samples with low, medium, and high Nf-L protein spikes, the precision as the mean %CV of three CSF samples (intra-assay and inter-assay), the mean dilutional linearity for three CSF samples against their dilution factors, and the mean %parallelism with the calibrator for five CSF samples (SD = Standard Deviation, R2 = linear regression coefficient).