Table 3.
Comparison of the sensitivity and specificity of dPCR in detecting different molecular targets of MERS-CoV and SARS-CoV-2.
| Virus type | Molecular targets | Sensitivity (SN) | Specificity (SP) | References |
|---|---|---|---|---|
| MERS-CoV | N, E, ORF 1ab | E: LOD of 167 RNA copies/reaction | 100% | [81] |
| N: LOD of 156 RNA copies/reaction | ||||
| ORF 1ab: LOD of 64 RNA copies/reaction | ||||
| SARS-CoV-2 | N | LOD and sensitivities of both qRT-PCR and dPCR are highly correlated. Mean detectable copies/samples using both methods are unclear | Unclear | [83] |
| N | LOD: 2.5 RNA copies/reaction as compared to 10 RNA copies/reaction of qRT-PCR (≥86%) | Unclear | [84] | |
| N | LOD: 0.00187 ng RNA compared to LOD of qRT-PCR of 0.0187 ng | 100% | [66] | |
| Could detect up to 0.08 virus copies/μL after 10-fold dilutions | ||||
| N | dPCR able to distinguish true positive and negative samples with low viral load (10-4 dilutions) while qRT-PCR was unable | 100% | [80] | |
| N | LOD: <2 RNA copies/μL for dPCR while qRT-PCR could not | Unclear | [86] | |
| RdRp | Median detection: 128 RNA copies/mL (~99%) | ~95% | [87] | |
| N, ORF 1ab | ORF 1ab: LOD of 401.8 RNA copies/mL | 100% | [74] | |
| N: LOD of 336.8 RNA copies/mL | ||||
| Overall sensitivity to detect positive Covid-19 samples: 67.65% |