Table 2.
Limit of detection of N1 and N2 assays using specimen matrix.
| SARS-CoV-2 target | Synthetic RNA spiked into bat guano samples prior to extraction (copies/µL) | TaqPath kit (mean Ct) | AgPath kit (mean Ct) | Synthetic RNA spiked into bat guano samples post-extraction (copies/µL) | TaqPath kit (mean Ct) | AgPath kit (mean Ct) |
|---|---|---|---|---|---|---|
| N1 | 1,000 | 35.6 | 35.6 | 1,000 | NT | NT |
| 100 | 38.3 | 38.4 | 100 | 28.0 | 29.0 | |
| 10 | U | U | 10 | 31.8 | 31.9 | |
| 1 | U | U | 1 | 34.4 | 35.3 | |
| 500 | 35.2 | 35.6 | 500 | NT | NT | |
| 250 | 36.8 | 36.6 | 250 | NT | NT | |
| N2 | 1,000 | 37.5 | 36.9 | 1,000 | NT | NT |
| 100 | U | U | 100 | 28.8 | 29.5 | |
| 10 | U | U | 10 | 31.8 | 32.8 | |
| 1 | U | U | 1 | 35.7 | 36.7 | |
| 500 | 36.2 | 35.6 | 500 | NT | NT | |
| 250 | 36.8 | 36.6 | 250 | NT | NT |
When the cycle threshold (Ct) 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.