Table 4.
The quantitative development of ten strains of SARS-CoV-2 after ten serial passages in Vero B4 cell culture flasks.
| Strain | Ct P0 | PFU/mL at P0 ( × 108) | Ct P10 | PFU/mL at P10 | Growth factor (%) |
|---|---|---|---|---|---|
| B5155 | 10 | 7.6 | – | 0 | 0 |
| B4926 | 10 | 7.6 | – | 0 | 0 |
| B5845 | 10 | 7.6 | – | 0 | 0 |
| A607 | 10 | 7.6 | 24 | 1.3 × 103 | 2 × 10-4 |
| A818 | 10 | 7.6 | 16 | 2.6 × 106 | 3 × 10-1 |
| A893 | 10 | 7.6 | 14 | 1.7 × 107 | 2 |
| A6301 | 10 | 7.6 | 12 | 2.6 × 106 | 15 |
| A7326 | 10 | 7.6 | 6 | 3.4 × 1010 | 4 × 103 |
| A6137 | 10 | 7.6 | 5 | 8.7 × 1010 | 1 × 104 |
| A4707 | 10 | 7.6 | 4 | 2.3 × 1011 | 3 × 104 |
Ct P0 and Ct P10 show the Ct values of the strains at passage 0 and 10, respectively, measured by RT-qPCR. The growth factor shows the percentage growth of the strain during the experiment (PFU/mL at P10 × 100)/(PFU/mL at P0).