Table 1. Test results for severe acute respiratory syndrome coronavirus 2 RdRp gene obtained from the proficiency test provider (expected value), Asan Medical Center, Seoul, and from participating laboratories according to the reagent used, South Korea, March 23–27, 2020*.
| Sample no. | Dilution | PowerChek |
Allplex |
Standard M, N = 6 | Laboratory-developed test, N = 5 | Real-Q, N = 1 | |||
|---|---|---|---|---|---|---|---|---|---|
| Expected value | Participating laboratories, N = 67 | Expected value | Participating laboratories, N = 38† | ||||||
| 41 | 1:2 × 105 | 33.60 | 33.64 + 1.73 | 34.37 | 34.64 + 2.23‡ | 30.38 (29.44–35.46)§ | 34.32 (32.57–34.62) | 38.27 | |
| 42 | 1:2 × 102 | 24.62 | 24.16 + 1.68 | 25.67 | 26.29 + 2.34 | 21.28 (19.98–27.54) | 25.94 (23.28–28.07) | 24.06 | |
| 43 | 1:2 × 104 | 30.73 | 30.60 + 1.45 | 31.34 | 32.05 + 2.43¶ | 27.49 (26.79–33.39) | 31.66 (30.01–32.83) | 30.54 | |
| 45 | 1:2 × 103 | 27.69 | 27.71 + 1.66 | 28.73 | 29.40 + 2.51# | 24.67 (23.51–31·21) | 28.12 (26.77–29.05) | 27.31 | |
| 46 | 1:2 × 103 | 24.82 | 25.61 + 0.76 | 26.12 | 26.07 + 1.11 | 22.18 (21.50–23.46) | 27.78 (25.74–28.49) | 26.61 | |
| 48 | 1:2 × 102 | 21.27 | 22.06 + 0.85 | 22.49 | 22.41 + 1.06 | 19.06 (17.20–19.86) | 24.07 (22.04–25.02) | 22.96 | |
| 49 | 1:2 × 105 | 32.14 | 32.57 + 0.96 | 32.55 | 32.35 + 1.13 | 29.36 (27.49–30.02) | 34.39 (32.18–35.42) | 33.36 | |
| 50 | 1:2 × 104 | 28.58 | 29.19 + 0.83 | 29.45 | 29.32 + 1.10 | 25.82 (24.20–27.01) | 31.29 (29.38–32.40) | 29.21 | |
*Cycle threshold values are shown. Mean + SD is shown for the results obtained by using the PowerChek 2019-nCoV and Allplex 2019-nCoV kits. Median and range are shown for the results obtained by using the Standard M nCoV-Detection and laboratory-developed tests. †For nCoV-20–41−45, the number of laboratories was 37. ‡Calculated after exclusion of negative results from 9 laboratories. §Calculated after exclusion of negative results from 1 laboratory. ¶Calculated after exclusion of negative results from 3 laboratories. #Calculated after exclusion of negative results from 1 laboratory.