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Published on: April 9, 2021
Evaluation of alternative RNA extraction methods for detection of SARS-CoV-2 in nasopharyngeal samples using the
Vinícius Pietta Perez1, Wallace Felipe Blohem Pessoa1, Bruno Henrique Andrade Galvão1
1Departamento de Fisiologia e Patologia, Centro de Ciências da Saúde, Universidade Federal da Paraíba, Campus I - Cidade Universitária s/n, João Pessoa, PB 58051-900, Brazil.
Background:
The efficiency of isolation and purification of the viral genome is a critical step to the accuracy and reliability of RT-qPCR to detect SARS-CoV-2. However, COVID-19 testing laboratories were overwhelmed by a surge in diagnostic demand that affected supply chains especially in low and middle-income facilities.
Objectives:
Thus, this study compares the performance of alternative methods to extraction and purification of viral RNA in samples of patients diagnosed with COVID-19.
Study Design:
Nasopharyngeal swabs were submitted to three in-house protocols and three commercial methods; viral genome was detected using the primer-probe (N1 and N2) described by CDC and viral load of samples were determined.
Results:
The in-house protocols resulted in detection of virus in 82.4 to 86.3% of samples and commercial methods in 94.1 to 98%. The disagreement results were observed in samples with low viral load or below the estimated limit of detection of RT-qPCR.
Conclusion:
The simplified methods proposed might be less reliable for patients with low viral load and alternative commercial methods showed comparable performance.
