Background SARS-CoV-2 Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) colorimetric detection is a sensitive and specific point-of-care molecular biology technique used to detect the virus in only 30 min. In this manuscript we have described a few nuances of the technique still not properly described in the literature: the presence of three colors clusters; the correlation of the viral load with the color change; and the importance of using an internal control to avoid false-negative results. Methods To achieve these findings, we performed colorimetric RT-LAMP assays of 466 SARS-CoV-2 RT-qPCR validated clinical samples, with color quantification measured at 434 nm and 560 nm. Results First we determinate a sensitivity of 93.8% and specificity of 90.4%. In addition to the pink (negative) and yellow (positive) produced colors, we report for the first time the presence of an orange color cluster that may lead to wrong diagnosis. We also demonstrated using RT-qPCR and RT-LAMP that low viral loads are related to Ct values > 30, resulting in orange colors. We also demonstrated that the diagnosis of COVID-19 by colorimetric RT-LAMP is efficient until the fifth symptoms day when the viral load is still relatively high. Conclusion This study reports properties and indications for colorimetric RT-LAMP as point-of-care for SARS-CoV-2 diagnostic, reducing false results, interpretations and optimizing molecular diagnostics tests application. Supplementary Information The online version contains supplementary material available at 10.1186/s10020-021-00289-0.
【저자키워드】 SARS-CoV-2, point of care, RT-LAMP, 【초록키워드】 Molecular biology, diagnostic, Diagnosis, Symptom, virus, diagnostics, molecular diagnostics, point-of-care, colorimetric detection, clinical samples, RT-LAMP, sensitivity, specificity, RT-qPCR, Viral, Internal control, Loop-mediated isothermal amplification, Viral load, Interpretation, Cluster, reverse transcription, molecular, false-negative results, correlation, quantification, false-negative, Ct values, lead, with color, color change, supplementary material, technique, indication, indications, manuscript, positive, Result, produced, resulting, described, performed, detect, addition, reducing, demonstrated, determinate, diagnosis of COVID-19, nuance, 【제목키워드】 Diagnosis, point-of-care, Loop-mediated isothermal amplification, Essential,