Details of the test methodology
General information:
The test has been performed using the in-house Direct RT-qPCR assay for the qualitative detection of SARS-CoV-2 nucleic acids in saliva samples as an aid in diagnosing patients for COVID-19.
Positive results are indicative of the presence of SARS-CoV-2 RNA in the submitted sample, however, clinical correlation with patient history and other diagnostic information is necessary to determine patient infection status. Positive results do not rule out bacterial infection or co-infection with other viruses. Negative results do not exclude SARS-CoV-2 infection and should not be used as the sole basis for patient management decisions. Negative results must be combined with clinical observations, patient history, and epidemiological information. A sample may have low clinical performance if submitted sub-optimally.
For further guidance please see: COVID-19 investigation and initial clinical management of possible cases https://bit.ly/3dNICKb.
Details specific to the UoN Asymptomatic Testing Service Direct RT-qPCR assay:
The test has been performed using Quantabio® UltraPlex 1-Step ToughMix in combination with US-CDC and Charité primer and probe sequences specific for SARS-CoV-2 genes N and E, respectively.
The limit of detection (LoD) of the assay has been determined to be 1 copy/µl for each target viral gene by testing samples at 1x, 2x, 4x, 8x and 16x the LoD with 36 or 18 replicates in 3 runs. The coefficient of variation (CV%) of the Ct values for these samples was less than or equal to 2.1%. No cross reactivity for the primer and probe sequences used has been detected across a range of common pathogens.