TABLE 1.
Intra- and interassay precision based on comparison with the 2nd HIV-1 WHO International Standard
| Assay | WHO International Standard |
Viral load detected (log10 copies/ml) |
Over-/underquantification with regard to diluted WHO International Standard [log10 copies/ml (95% CI)] | ||
|---|---|---|---|---|---|
| Dilution level | Dilution (log10 copies/ml)a | Meanb (95% CI) | SD, totalc | ||
| Abbott RT | Low | 2.29 | 1.99 (1.85; 2.13) | 0.14 | −0.30 (−0.44; −0.16) |
| High | 4.38 | 4.12 (4.07; 4.17) | 0.04 | −0.26 (−0.31; −0.21) | |
| Roche CAP/CTM-48 V2 | Low | 2.30 | 2.61 (2.52; 2.69) | 0.13 | 0.31 (0.22; 0.39) |
| High | 4.40 | 4.57 (4.50; 4.63) | 0.13 | 0.17 (0.10; 0.23) | |
a
Conversion factor used for Abbott RT was 0.58 copies/ml per IU/ml and for Roche CAP/CTM-48 V2, 0.6 copies/ml per IU/ml.
b
Mean value over 5 separate runs with four replicates each.
c
Level acceptable according to manufacturer's specifications: ≤0.25 for Abbott RT and ≤0.3 for Roche CAP/CTM-48 V2.