DESIGN OF A LABORATORY DEVELOPED ASSAY TO AID IN THE DETECTION OF SARS-COV-2 VIRUS RNA IN OROPHARYNGEAL AND NASOPHARYNGEAL SWABS ADAPTED FROM THE CDC PROTOCOL

INTRO: SARS-CoV-2 is a single-strand enveloped RNA virus belonging to the family Coronaviridae. It was first recognized in late 2019 as causing COVID-19, and later declared a pandemic. The development of this assay aided in the detection of positive cases early in the pandemic which in turn facilitated the isolation of infected individuals to minimize the spread. METHODS: The SARS-CoV-2 RNA detection by real time RT-PCR is a molecular in vitro diagnostic test that aids in the detection and diagnosis of SARS-CoV-2 in nasopharyngeal and oropharyngeal specimens. This test is based on nucleic acid extraction and amplification technology and uses oligonucleotide primers and dual-labeled hydrolysis probes. RNA is isolated and purified from specimens using the Abbott m2000sp. This technology uses magnetic particles to capture and purify the RNA. The bound RNA is eluted and transferred to a 96 deep-well plate and is ready for amplification. The master mix is prepared manually and is added to a PCR plate together with the extracted RNA. The RNA is reverse transcribed to cDNA and subsequently amplified in the Abbott m2000rt. In this process, the probe anneals to a specific target sequence located between the forward and reverse primers. During the extension step of the PCR cycle, the 5’ nuclease activity of Taq polymerase degrades the probe, causing the reporter dye molecules to be cleaved from their respective probes, increasing the fluorescence intensity. Fluorescence intensity is monitored at each PCR cycle on the Abbott m2000rt instrument. FINDINGS: The clinical evaluation was performed by testing patient samples in a blinded fashion. The performance of SARS-CoV-2 Assay was established using 60 clinical specimens. The positive and negative percent agreements were analyzed by comparing the SARS-CoV-2 Assay results to Seegene's AllplexTM 2019-nCoV which showed 100% concordance. CONCLUSION: This assay demonstrated accuracy and reproducibility for the detection of SARS-CoV-2.