Table 2.
Comparison of real-time PCR (rtPCR) and droplet digital PCR (ddPCR) assays using serially diluted porcine epidemic diarrhea virus plasmids.
| Concentration of PUC57-N plasmid (copies/μL) | rtPCR (mean Cq value) | ddPCR (mean concentration,* copies/μL) |
|---|---|---|
| 4 × 108 | 11.0 | ND |
| 4 × 107 | 14.7 | ND |
| 4 × 106 | 18.2 | 100,000 |
| 4 × 105 | 21.7 | 2,420 |
| 4 × 104 | 25.2 | 243 |
| 4 × 103 | 28.6 | 23.3 |
| 4 × 102 | 32.1 | 1.47 |
| 4 × 101 | Neg | 0.26 |
Cq = quantification cycle; ND = not detected; Neg = 1 replicate of 3 was negative.
*
Concentration based on ddPCR detection.