Diagnovital SARS-CoV-2 Multiplex
Diagnovital SARS-CoV-2 Multiplex is a real-time RT-PCR-based test intended for the qualitative detection of nucleic acid from the SARS-CoV-2 in upper respiratory specimens (nasal, mid-turbinate, nasopharyngeal and oropharyngeal swabs) and BAL specimens from individuals suspected of COVID-19 by their healthcare provider.
Diagnovital SARS-CoV-2 Multiplex is a qualitative test for the detection of the 2019 novel coronavirus (SARS-CoV-2) in upper respiratory swab samples collected in Copan Universal Transport Medium System (UTM-RT) or BD Universal Viral Transport System (UVT) and is run on the BIO-RAD CFX96-IVD, Qiagen Rotor-Gene Q, Applied Biosystems ABI 7500 Fast Real time PCR Dx, Thermo Fisher QS5 Dx, DNA Technologie DTPrime5, and Analytik Jena qTower3G Real Time Machine. In addition, the test utilizes external controls (low titer positive control and a negative control).
Diagnovital SARS-CoV-2 Multiplex test is based on conventional RT-PCR technology including extraction and purification of the nucleic acid genome of SARS-CoV-2 followed by PCR amplification and detection. Nucleic acid from patient samples and controls are extracted in parallel using the Thermo Fischer MagMax, RTA Viral RNA Isolation Kit, Qiagen QIAamp MinElute Virus Spin kit, or Roche High Pure Viral RNA Kit, SphaeraMag DNA/RNA Isolation Kit. Nucleic acid is released by the lysis reagent and bound to the silica columns or magnetic beads. Unbound substances and impurities, such as denatured protein, cellular debris and potential PCR inhibitors, are removed with subsequent wash steps and purified nucleic acid is eluted silica columns with elution buffer. External controls (positive and negative) are processed in the same way with each run.
Selective amplification of target nucleic acid from the sample is achieved by the use of target-specific forward and reverse primers and probes specific to conserved regions of the ORF1ab and N genes for SARS-CoV-2.
Selective amplification of RNA Internal Control is achieved by the use of non-competitive, sequence specific forward and reverse primers and a probe which have no homology with the coronavirus genome. A thermostable DNA polymerase enzyme is used for amplification.
The Diagnovital SARS-CoV-2 Multiplex master mix contains detection probes for the two SARSCoV-2 targets and one for the internal RNase P. Probes are each labeled with fluorescent dyes that act as a reporter. Each probe also has a second dye which acts as a quencher. When not bound to the target sequence, the fluorescent signals of the intact probes are suppressed by the quencher dye. During the PCR amplification step, hybridization of the probes to the specific single-stranded DNA template results in cleavage of the probe by the 5′ to 3′ exonuclease activity of the DNA polymerase resulting in separation of the reporter and quencher dyes and the generation of a fluorescent signal. With each PCR cycle, increasing amounts of cleaved probes are generated and the cumulative signal of the reporter dye increases concomitantly. Each reporter dye is measured at defined wavelengths, which enables simultaneous detection and discrimination of the amplified coronavirus targets.