Table 2.
Back calculation and percent accuracy of standard curvesa
| Nominal concentration (μg/mL)b | Experimentally determined a | Proteins used to generate the standard curve |
||||
|---|---|---|---|---|---|---|
| AMA1-C1 | AMA1-C2 | BSAM-2 | MSP142-3D7 | MSP142-C1 | ||
| 400 (500)d | Concentration | 397 ± 5.3 | 398 ± 3.4 | 395.2 ± 0.8 | 394.3 ± 2.7 | 492.7 ± 3.7 |
| % Accuracy | 98.9 ± 1.0 | 99.1 ± 0.5 | 98.8 ± 0.2 | 98.6 ± 0.7 | 98.5 ± 0.7 | |
| 200 (250) | Concentration | 203 ± 9.9 | 204 ± 8.3 | 206.5 ± 2.4 | 206.0 ± 6.8 | 257.4 ± 7.6 |
| % Accuracy | 95.9 ± 2.5 | 96.4 ± 2.6 | 96.7 ± 1.2 | 96.9 ± 3.3 | 97.0 ± 3.0 | |
| 100 (125) | Concentration | 105 ± 6.8 | 101 ± 6.7 | 106.6 ± 2.7 | 109.4 ± 3.9 | 136.2 ± 0.9 |
| % Accuracy | 93.3 ± 4.4 | 95.8 ± 4.9 | 93.4 ± 2.7 | 90.6 ± 3.9 | 91.1 ± 0.7 | |
| 50 (62.5) | Concentration | 55 ± 0.4 | 51.8 ± 4.2 | 51.5 ± 1.0 | 55.1 ± 0.2 | 70.6 ± 1.8 |
| % Accuracy | 90.5 ± 0.8 | 94.3 ± 7.1 | 96.9 ± 2.0 | 89.9 ± 0.4 | 87.0 ± 2.8 | |
| 25 (31.25) | Concentration | 26 ± 1.5 | 25 ± 1.7 | 22.9 ± 0.6 | 24.5 ± 2.3 | 32.3 ± 1.5 |
| % Accuracy | 93.3 ± 1.5 | 95.2 ± 4.3 | 91.7 ± 2.3 | 93.3 ± 5.1 | 95.3 ± 2.4 | |
| 12.5 (15.63) | Concentration | 10.2 ± 2.7 | 11.3 ± 1.7 | 9.0 ± 0.8 | 8.9 ± 0.3 | 12.8 ± 1.7 |
| % Accuracy | 80.2 ± 20.0 | 88.6 ± 12.6 | 72.0 ± 6.7 | 71.5 ± 2.1 | 82.0 ± 11.0 | |
a
Back calculation was performed by converting the observed readings of the standards to concentrations of antigens using linear regression equations; Percent accuracy = (|calculated concentration − nominal concentration|/nominal concentration) × 100. Results are means ± standard deviation of 3–7 independent OPA assays.
b
A known amount of indicated protein was freshly prepared on Alhydrogel®.
d
The nominal concentrations of MSP142-C1 prepared by 2-fold dilutions from 500 μg/mL.