Development of RNA-Based Assay for Rapid Detection of SARS-CoV-2 in Clinical Samples

• Published in: Intervirology Vol. 65; no. 4; pp. 181 - 187
• Main Authors: Kumar, Vinod, Mishra, Suman, Sharma, Rajni, Agarwal, Jyotsna, Ghoshal, Ujjala, Khanna, Tripti, Sharma, Lokendra K., Verma, Santosh Kumar, Mishra, Prabhakar, Tiwari, Swasti
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.10.2022; Karger Publishers
• Subjects: Coronaviruses; Development and progression; Genes; Health aspects; Medical screening; Papillomavirus infections; Research Article; RNA; Severe acute respiratory syndrome; India; Colorimetric test; Diagnosis; Coronavirus disease-19; Ribonucleic acid; Coronavirus disease
• ISSN: 0300-5526; 1423-0100; 1423-0100
• DOI: 10.1159/000522337

Introduction: The ongoing spread of pandemic coronavirus disease-19 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of growing concern. Rapid diagnosis and management of SARS-CoV-2 are crucial for controlling the outbreak in the community. Here, we report the development of a first rapid-colorimetric assay capable of detecting SARS-CoV-2 in the human nasopharyngeal RNA sample in less than 30 min. Method: We utilized a nanomaterial-based optical sensing platform to detect RNA-dependent RNA polymerase gene of SARS-CoV-2, where the formation of oligo probe-target hybrid led to salt-induced aggregation and change in gold-colloid color from pink to blue visibility range. Accordingly, we found a change in colloid color from pink to blue in assay containing nasopharyngeal RNA sample from the subject with clinically diagnosed COVID-19. The colloid retained pink color when the test includes samples from COVID-19 negative subjects or human papillomavirus-infected women. Results: The results were validated using nasopharyngeal RNA samples from positive COVID-19 subjects (n = 136). Using real-time polymerase chain reaction as gold standard, the assay was found to have 85.29% sensitivity and 94.12% specificity. The optimized method has detection limit as little as 0.5 ng of SARS-CoV-2 RNA. Conclusion: We found that the developed assay rapidly detects SARS-CoV-2 RNA in clinical samples in a cost-effective manner and would be useful in pandemic management by facilitating mass screening.