Rapid visual detection of SARS-CoV-2 by colorimetric loop-mediated isothermal amplification

Viral Rna ◽

Amplification Technique ◽

Higher Sensitivity

Evaluation of the performance of a new set of primers defined from the ORF1ab sequence, and its combination with a previously published set of primers from the N sequence, to detect SARS-CoV-2 RNA by the loop-mediated isothermal amplification technique is presented. The ORF1ab primer set enables visual detection of SARS-CoV-2 RNA in 16 min. In addition, a simultaneous reaction with both ORF1ab and N primers allows for higher sensitivity of detection, particularly when low numbers of copies are present (250 viral RNA copies). Further, the protocol is able to detect viral RNA in saliva samples. The procedure reported could be easily implemented in the generation of a new and sensitive rapid point-of care device for SARS-CoV-2 RNA visual detection.

Development of a loop-mediated isothermal amplification technique and comparison with quantitative real-time PCR for the rapid visual detection of canine neosporosis

Parasites & Vectors ◽

10.1186/s13071-017-2330-2 ◽

2017 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Aongart Mahittikorn ◽

Nipa Thammasonthijarern ◽

Amonrattana Roobthaisong ◽

Ruenruetai Udonsom ◽

Supaluk Popruk ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Visual Detection ◽

Quantitative Real Time Pcr ◽

Amplification Technique

Point-of-care and visual detection of Salmonella spp. and Cronobacter spp. by multiplex loop-mediated isothermal amplification label-based lateral flow dipstick in powdered infant formula

International Dairy Journal ◽

10.1016/j.idairyj.2021.105022 ◽

2021 ◽

pp. 105022

Author(s):

Xinyan Yang ◽

Yujun Jiang ◽

Yang Song ◽

Xue Qin ◽

Yuwei Ren ◽

...

Keyword(s):

Infant Formula ◽

Visual Detection ◽

Point Of Care ◽

Lateral Flow ◽

Powdered Infant Formula ◽

Salmonella Spp ◽

Lateral Flow Dipstick

Evaluation of a Loop-Mediated Isothermal Amplification Technique for the Rapid Visual Detection of Hepatozoon canis Infection

Acta Parasitologica ◽

10.2478/s11686-019-00143-8 ◽

2019 ◽

Vol 65 (1) ◽

pp. 151-155

Author(s):

Manraj Deep Singh ◽

Harkirat Singh ◽

Nirbhay Kumar Singh ◽

Niraj Kumar Singh ◽

Naresh Kumar Sood ◽

...

Keyword(s):

Visual Detection ◽

Hepatozoon Canis ◽

Amplification Technique

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 ◽

10.1186/s10020-021-00289-0 ◽

2021 ◽

Vol 27 (1) ◽

Author(s):

Bruna de Oliveira Coelho ◽

Heloisa Bruna Soligo Sanchuki ◽

Dalila Luciola Zanette ◽

Jeanine Marie Nardin ◽

Hugo Manuel Paz Morales ◽

...

Keyword(s):

Viral Load ◽

Internal Control ◽

Reverse Transcription ◽

Color Change ◽

Point Of Care ◽

Colorimetric Detection ◽

False Negative ◽

Loop Mediated Isothermal Amplification

Clinical Samples ◽

Abstract 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.