SARS-CoV-2 identification


RT-PCR testing for SARS-CoV-2 virus identification

RT-PCR SARS-CoV-2 test is a real-time polymerase chain reaction (PCR) test for qualitative detection of SARS-CoV-2 nucleic acid in upper respiratory tract samples. The results are used to identify SARS-CoV-2 RNA. Sars-CoV-2 RNA is usually detectable in oropharyngeal and nasopharyngeal samples in the acute phase of infection.

Biological sample
Oropharyngeal / nasopharyngeal exudate

The real-time SARS-CoV-2 RT-PCR test targets two distinct regions of the SARS-CoV-2 genome: the N gene and the ORF1ab gene. Amplification of both targets results in a positive (detectable) test result, while amplification of one of the two targets results in an inconclusive result, and if neither gene is amplified, the test is negative (undetectable).

Samples with inconclusive test results will be confirmed by a second PCR reaction for the ORF1ab gene.
Positive results do not rule out bacterial infection or co-infection with other viruses.
Negative results do not rule out SARS-CoV-2 infection and should not be used as the sole basis for medical decisions. Negative results should be combined with clinical observations, patient history and epidemiological information.

Rapid in vitro diagnostic testing for SARS-CoV-2 qualitative detection (SARS-CoV-2 antigen test)

Biological sample
Nasopharyngeal exudate

Principle of the method: CerTest SARS-CoV-2 rapid test is based on the principle of qualitative immunochromatographic analysis for the qualitative detection of SARS-CoV-2 in nasopharyngeal buffer samples from patients suspected of being infected with COVID-19.

The band consists of a nitrocellulose membrane previously coated with murine monoclonal antibodies, on the test line (T), in the results window, against SARS-CoV-2 and with rabbit polyclonal antibodies, on the control line (C), against a certain protein. The absorbent label / sample buffer is sprayed with a test solution for labels (murine monoclonal antibodies anti-SARS-CoV-2) conjugated with red polystyrene latex and a solution for the control label (specific binding protein) conjugated with green polystyrene latex , forming colored conjugate complexes.

The presence of the green control line appears in the case of each reaction for 1) checking the addition of a sufficient volume, 2) obtaining an adequate flow rate and 3) an internal control for the reagents.

The detection limit value (typical) for CerTest SARS-CoV-2 is 1.0 ng / ml of recombinant SARS-CoV-2 protein or 1×103 TCID50 / ml from 2019nCoV / USA-WA1 / 2020.