Table 1.
Comparisons of RT-qPCR and ddPCR results obtained using serial dilutions of SARS-CoV-2-infected samples and negative controls
| Samples | RT-qPCR (Cq) | ddPCR (droplets) | |||
|---|---|---|---|---|---|
| N | RdRP (IP4) | N positive | RdRP (IP4) positive | Accepted | |
| A549 24H 1.0 E-02 | 15.99 | 16.01 | 13566 | 13566 | 13566 |
| A549 24H 1.0 E-03 | 19.09 | 19.23 | 15106 | 15106 | 15106 |
| A549 24H 1.0 E-04 | 22.24 | 22.53 | 12839 | 12839 | 12839 |
| A549 24H 1.0 E-05 | 25.64 | 26.01 | 8435 | 3626 | 13203 |
| A549 24H 1.0 E-06 | 29.20 | 29.26 | 1114 | 350 | 11081 |
| A549 24H 1.0 E-07 | 32.60 | 32.90 | 160 | 45 | 13507 |
| A549 24H 1.0 E-08 | 34.94 | 37.39 | 15 | 2 | 12290 |
| 200132 E-03 | 23.36 | 21.79 | 6415 | 6332 | 10286 |
| 200132 E-04 | 27.14 | 25.62 | 5075 | 4256 | 13375 |
| 200132 E-05 | 29.65 | 28.11 | 783 | 564 | 12615 |
| 200132 E-06 | 32.90 | 31.44 | 34 | 32 | 11851 |
| 200132 E-07 | 38.07 | 37.33 | 45 | 34 | 14180 |
| 200132 E-08 | N/A | N/A | 1 | 1 | 15403 |
| 293T (1) | 39.54 | N/A | 0 | 0 | 12993 |
| 293T (2) | N/A | N/A | 1 | 0 | 11477 |
| H20 | N/A | N/A | 0 | 0 | 13076 |
Tenfold dilutions of RNA extracts from an infected cell line (A549-ACE2) and a patient (n#200132) diagnosed as strongly positive for SARS-CoV-2 RNA were compared using RT-qPCR and ddPCR. Accepted droplets correspond to the total count of bona fide droplets as detected in a given well by the droplet reader. RNA extracted from uninfected 293T cells was used as a negative control.