PAN AFRICAN JOURNAL OF LIFE SCIENCES
Volume 4, No. 2, August 2020
Understanding the Use of Real Time Reverse Transcriptase-Polymerase Chain Reaction (rRT-PCR) For Covid-19 Diagnosis
Adesola O. Olalekan1,2*, Bamidele A. Iwalokun2,3,4 Olutoyin C. Adekunle5, Hussaini A. Makun4, Tatfeng Mirabeau6, Oluyemi Akinloye1,2
1Molecular Diagnostics Research Laboratory, Department of Medical Laboratory Science, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Idi-araba, Lagos
2Centre for Genomics of Non-communicable Diseases and Personalized Healthcare, University of Lagos
3Molecular Biology & Biotechnology Department, Nigerian Institute of Medical Research, Lagos
4African Centre for Excellence for Mycotoxins and food Safety, Federal University of Technology, Niger State
5Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo
6Department of Medical Laboratory Science, Niger Delta University.
Background: Adequate knowledge of real time Reverse Transcriptase-Polymerase Chain Re-action (rRT-PCR) is critical for accurate implementation of the assay, interpretation of results and report-ing. This mini-review describes the principles, procedures, and level of development of rRT-PCR assays for the control of the COVID-19 pandemic.
Methods: A narrative review was carried out to describe the principles of rRT-PCR, provide an update on the landscape of rRT-PCR protocols and elucidate the process control involved in pre-analytical, analytical and post-analytical stages of COVID-19 testing .
Review Findings: The rRT-PCR is currently considered to be the acceptable standard for confirming COVID-19 diagnosis based on SARS-CoV-2 RNA detection via conversion to cDNA and amplification of target genes in real time using sequence specific TaqMan® probes. Available evidence indicates that different rRT-PCR protocols varying in number and type of target genes within SARS-CoV-2 genome are currently available for validation and emergency use approval (EUA) in pandemic countries. A total of 1 – 3 target genes, comprising the ORF1a, ORF1b, RNA dependent RNA polymerase (RdRp), Nucleoplasid protein gene (N), Spike glycoprotein gene (S) and Envelope protein gene (E) are detected by these proto-cols.
Conclusion: rRT-PCR remains the most sensitive method for confirming, monitoring and managing COVID-19 disease in the ongoing pandemic in all affected countries. The need for validation of every rRT-PCR protocol prior to deployment for COVID-19 testing and research into the development of alternative testing protocols are strongly recommended
Keywords: COVID -19, rRT-PCR, SARS-CoV-2, biological samples, target genes