Article
Essential properties and pitfalls of colorimetric Reverse Transcription Loop‑mediated Isothermal Amplification as a point‑of‑care test for SARS‑CoV‑2 diagnosis
Registro en:
COELHO, Bruna de Oliveira et al. Essential properties and pitfalls of colorimetric reverse transcription loop‑mediated isothermal amplification as a point‑of‑care test for SARS‑CoV‑2 diagnosis. Molecular Medicine, v.27, n. 30, p. 1–11, 2021.
1528-3658
Autor
Coelho, Bruna de Oliveira
Sanchuki, Heloisa Bruna Soligo
Zanette, Dalila Lucíola
Nardin, Jeanine Marie
Morales, Hugo Manuel Paz
Fornazari, Bruna
Aoki, Mateus Nóbrega
Blanes, Lucas
Resumen
SARS-CoV-2 Reverse Transcription Loop-mediated Isothermal Amplifcation (RT-LAMP) colorimetric detection is a sensitive and specifc 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. To achieve these fndings, we performed colorimetric RT-LAMP assays of 466 SARS-CoV-2 RT-qPCR validated clinical samples, with color quantifcation measured at 434 nm and 560 nm. First we determinate a sensitivity of 93.8% and specifcity of 90.4%. In addition to the pink (negative) and yellow (positive) produced colors, we report for the frst 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 efcient until the ffth symptoms day when the viral load is still relatively high. 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.