Table 1.
Analytical sensitivity of N1 and N2 assays using TaqPath and AgPath kits.
| SARS-CoV-2 target | RNA from virus isolate with known titer (TCID50/mL) | TaqPath kit (mean Ct) | AgPath kit (mean Ct) | SARS-CoV-2 plasmid (copies/reaction) | TaqPath kit (mean Ct) | AgPath kit (mean Ct) |
|---|---|---|---|---|---|---|
| N1 | 100,000 | 17.5 | NT | 100,000 | 25.0 | 14.8 |
| 10,000 | 21.3 | 21.6 | 10,000 | 28.4 | 28.2 | |
| 1,000 | 25.0 | 25.1 | 1,000 | 31.7 | 31.8 | |
| 100 | 28.3 | 28.5 | 100 | 34.4 | 34.9 | |
| 10 | 32.1 | 32.6 | 10 | 35.5 | U | |
| 1 | 35.6 | 36.6 | 1 | U | U | |
| 0.1 | U | 38.9 | 0.1 | NT | NT | |
| 0.01 | U | U | 0.01 | NT | NT | |
| N2 | 100,000 | 17.3 | NT | 100,000 | 26.1 | 25.1 |
| 10,000 | 21.2 | 22.4 | 10,000 | 30.2 | 29.1 | |
| 1,000 | 25.0 | 25.9 | 1,000 | 33.8 | 32.8 | |
| 100 | 28.4 | 29.4 | 100 | 37.7 | 36.5 | |
| 10 | 32.5 | 33.6 | 10 | U | U | |
| 1 | 36.1 | 35.2 | 1 | U | U | |
| 0.1 | U | 38.9 | 0.1 | NT | NT | |
| 0.01 | U | U | NT | NT | NT |
When the cycle threshold (Ct) value of one or more of the replicates per dilution was undetermined, the mean Ct value of this dilution was considered undetermined.
NT = not tested; U = undetermined.