Comparative Analysis of Threshold Cycle Results for RNA Extraction in SARS-CoV-2 RT-qPCR Using Magnetic Beads and Spin Column Methods

Abstract

Coronavirus Disease-2019 (COVID-19) belongs to the large family of SARS-CoV viruses, initially emerging in 2002-2003. In humans, this virus triggers respiratory infectious diseases. COVID-19, a new variant of SARS-CoV, was identified in humans following an unprecedented incident in Wuhan, China, in December 2019. This virus typically manifests mild symptoms, including a runny nose, sore throat, cough, and fever. The Nucleic Acid Amplification Test (NAAT), specifically the realtime Reverse Transcription Polymerase Chain Reaction (rRT-PCR) examination, is recommended by the World Health Organization (WHO) for diagnosing COVID-19. This study assessed potential differences in Threshold Cycle results during RNA extraction using magnetic beads compared to spin columns in the SARS-CoV-2 rRT-PCR method. The population for this study was selected through accidental sampling from nasopharyngeal and oropharyngeal swabs of COVID-19 patients obtained between December 2022 and April 2023, with Threshold Cycle values <30,000. The samples were stored at -80°C. The findings revealed that the average N (VIC) was 23.359, and RdRP (FAM) was 25.558 in the Magnetic Beads method, indicating a lower value compared to the average N (VIC) of 29.200 and RdRP (FAM) of 29.661 in the Spin Column method. This suggests that the Magnetic Beads method exhibited greater sensitivity than the Spin Column method. The statistical analysis confirmed these differences, with a P value of 0.003 in N (VIC) and the P value of 0.000 in RdRP (FAM). Consequently, it can be concluded that there is a significant 19.5% difference in the Threshold Cycle during RNA extraction using Magnetic Beads and Spin Column in the examination of the SARS-CoV-2 rRT-PCR method. Keywords: Sars-CoV-2; rRT-PCR; Magnetic Beads; Spin Column; Threshold Cycle.