Table 1.
Sample sets characteristics
| Sample set | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| n specimens | 30 | 30 | 90 | 60 | 60 |
| Previous rRT-PCR | + | + | + (3 viral genes) | + (N gene only) | - |
| Ct range N gene | random | random | Wide 15–40 |
Low 30–35 Very low 36–40 |
not detected |
| Medium | UTM | RF water | RF water | RF water | RF water |
| Storage | − 70 °C | − 70 °C | − 70 °C | − 70 °C | − 70 °C |
| Thermal lysis | Y vs. N | Y vs. N | Y | Y | Y |
| RNA extraction | Y vs. N | Y vs. N | N | N | N |
| Direct rRT-PCR | Y | Y | Y | Y | Y |
| Dilution in RF water | 1/1 vs. 1/2 vs. 1/5 vs. 1/10 | 1/1 vs. 1/2 vs. 1/5 vs. 1/10 | 1/2 | 1/2 | 1/2 |
| Proteinase K | N | N | Y vs. N | Y vs. N | Y vs. N |
RF RNase-free, Y yes, N no