TABLE 2.
Precision and accuracy of the 4-plex array for the analysis of malaria proteins and CRP in human blood specimens
| Target | Nominal concn | Intra-assay (n = 20) |
Interassay (n = 20) |
||||
|---|---|---|---|---|---|---|---|
| Mean Concn | Precision (CV%)a | Accuracy (%) | Mean concn | Precision (CV%) | Accuracy (%) | ||
| HRP2 (pg/ml) | 23.0 | 22.0 | 6.7 | 95.7 | 21.7 | 11.4 | 94.2 |
| 126.5 | 127.1 | 10.0 | 100.5 | 128.2 | 14.0 | 101.3 | |
| 230.0 | 233.0 | 10.3 | 101.3 | 251.3 | 16.0 | 109.3 | |
| Pan LDH (pg/ml) | 450.0 | 379.6 | 5.2 | 84.4 | 407.2 | 8.9 | 90.5 |
| 2,475.0 | 2,577.5 | 6.9 | 104.1 | 2,402.2 | 10.3 | 97.1 | |
| 4,500.0 | 5,120.6 | 5.9 | 113.8 | 4,769.9 | 12.9 | 106.0 | |
| P. vivax LDH (pg/ml) | 22.8 | 21.0 | 4.2 | 91.9 | 20.9 | 9.0 | 91.6 |
| 125.4 | 127.0 | 5.7 | 101.2 | 118.2 | 10.1 | 94.3 | |
| 228.0 | 246.2 | 5.3 | 108.0 | 229.5 | 11.2 | 100.7 | |
| CRP (ng/ml) | 827.0 | 717.1 | 9.9 | 86.7 | 838.0 | 8.5 | 101.4 |
| 3,813.0 | 3,590.2 | 8.7 | 94.1 | 3,876.9 | 11.6 | 101.7 | |
| 6,800.0 | 6,825.7 | 9.4 | 100.4 | 6,572.9 | 13.3 | 96.7 | |
a
The assay CV% for each protein concentration was calculated by finding the standard deviation of replicates, dividing that by the mean, and then multiplying by 100. The mean concentration was compared to the predetermined concentration of specimen to determine the accuracy % of the ELISA. The accuracy % was calculated as the value of (observed-expected)/expected × 100.