Initial limit of detection results for laboratory developed test (LDT) qPCR assay
2019-nCoV-N1 | |||||||
Genomes/µL | 0 | 0.37 | 1.11 | 3.3 | 10 | 100 | 1000 |
% positive (out of 3) | – | 0% | 67% | 100% | 100% | 100% | 100% |
Mean Ct (SD) | – | – | – | 34.8 (0.35) | 33.14 (0.13) | 29.89 (0.15) | 25.99 (0.1) |
2019-nCoV-N2 | |||||||
Genomes/µL | 0 | 0.37 | 1.11 | 3.3 | 10 | 100 | 1000 |
% positive (out of 3) | – | 33% | 67% | 100% | 100% | 100% | 100% |
Mean Ct (SD) | – | – | – | 40 (0) | 37.98 (0.51) | 34.17 (0.31) | 29.66 (0.21) |
RNaseP | |||||||
Genomes/µL | 0 | 0.37 | 1.11 | 3.3 | 10 | 100 | 1000 |
% positive (out of 3) | 67% | 100% | 100% | 100% | 100% | 100% | 100% |
Mean Ct (SD) | 28.01 (0.02) | 28.0 (0.02) | 28 (0.02) | 28 (0.13) | 28 (0.04) | 29.01 (0.05) | 27.96 (0.2) |
Mean Ct and per cent positivity of a dilution series of samples spiked with in-vitro transcribed RNA of the entire N-gene performed in triplicate are shown for SARS-CoV-2 N1 and N2 targets and a human RNase P control. Concentrations of the IVT RNA dilution series are reported as genomes per microlitre. Results indicate that the lowest concentration at which 100% of samples run in triplicate were detected for both N1 and N2 targets of SARS-CoV-2 genome was 3.3 genomes per microlitre. RNase P primers were used as a positive control to ensure proper specimen collection and monitor against substantial extraction, PCR inhibition, or reagent failure.