RESUMEN
BACKGROUND: High cost of commercial RNA extraction kits limits the testing efficiency of SARS-CoV-2. Here, we developed a simple nucleic acid extraction method for the detection of SARS-CoV-2 directly from nasopharyngeal swab samples. METHODS: A pH sensitive dye was used as the end point detection method. The obvious colour changes between positive and negative reactions eliminates the need of other equipment. RESULTS: Clinical testing using 260 samples showed 92.7% sensitivity (95% CI 87.3-96.3%) and 93.6% specificity (95% CI 87.3-97.4%) of RT-LAMP. CONCLUSIONS: The simple RNA extraction method minimizes the need for any extensive laboratory set-up. We suggest combining this simple nucleic acid extraction method and RT-LAMP technology as the point-of care diagnostic tool.
Asunto(s)
Prueba de COVID-19 , COVID-19 , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/virología , Prueba de COVID-19/métodos , Humanos , Técnicas de Diagnóstico Molecular/métodos , Nasofaringe/virología , Técnicas de Amplificación de Ácido Nucleico/métodos , Sistemas de Atención de Punto , ARN Viral/análisis , ARN Viral/genética , ARN Viral/aislamiento & purificación , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Current assays for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rely on time consuming, costly and laboratory based methods for virus isolation, purification and removing inhibitors. To address this limitation, we propose a simple method for testing RNA from nasopharyngeal swab samples that bypasses the RNA purification step. METHODS: In the current project, we have described two extraction-free reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays for the detection of SARS-CoV-2 by using E gene and RdRp gene as the targets. RESULTS: Here, results showed that reverse transcription loop-mediated isothermal amplification assays with 88.4% sensitive (95% CI: 74.9-96.1%) and 67.4% sensitive (95% CI: 51.5-80.9%) for E gene and RdRp gene, respectively. CONCLUSION: Without the need of RNA purification, our developed RT-LAMP assays for direct detection of SARS-CoV-2 from nasopharyngeal swab samples could be turned into alternatives to qRT-PCR for rapid screening.