Keywords
COVID-19
RT-PCR
variants
How to Cite
Abstract
Introduction: Most of the RT-PCR tests used by commercial and public health laboratories detect if a person carries the SARS-CoV-2 virus but cannot determine the variant. Thus, it may be of interest to have tests that facilitate the identification of one of the two main variants of concern with the highest circulation today: Delta and Omicron. Objectives: The aim of this study was to develop a commercial test, for research use only, for the detection of the Delta and Omicron BA.1 variants. Materials and methods: Primers and probes were selected to detect a unique and specific region with mutations of the gene encoding the Spike protein in the Delta and Omicron BA.1 variants, and its version without mutation. A product containing all the necessary components was designed to detect and amplify viral RNA using the real-time RT-PCR technique. Analytical validations were performed with synthetic material of each variant and clinical validations with a panel of 110 samples positive for SARS-CoV-2, previously sequenced for classification of its variants. Results: A fast, direct, and accessible method was developed and validated for the detection of the Delta and Omicron BA.1 variants by real-time RTPCR, with a detection limit of less than 10 cp/μL and high sensitivity and specificity (100%). Conclusions: Realtime RT-PCR-based tests can be used to rapidly monitor SARS-CoV-2 variants of concern in resource-limited countries, although they require updates as new variants emerge.
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