RT-LAMP: an emerging technology for reliable, rapid, and cost-efficient detection of COVID-19 and other viruses

Addressing the global need for reliable, cost-efficient, and rapid COVID-19 diagnosis at the point-of-care

The highly-infectious novel coronavirus, SARS-CoV-2 is the cause of Coronavirus disease-2019 (COVID-19) and the driver behind the current pandemic, which has caused severe health and financial consequences the world over. Currently, there is a huge effort being undertaken by governments around the world to restore a sense of normalcy by slowing down the spread of the virus by using different kinds of testing methods in order to cut infection chains as early as possible. A strong need has developed for rapid, high-throughput, and precise SARS-CoV-2 detection technology to control and contain the virus at the point-of-care. While reverse transcription polymerase chain reaction (RT-PCR) is considered to be the current gold standard in SARS-CoV-2 detection, a disruptive new technology has recently emerged – the RT-LAMP method.

Dotz’ rapid, precise, and high-throughput RT-LAMP diagnostic platform

What is RT-LAMP?

Reverse-Transcription Loop-Mediated Isothermal Amplification, or RT-LAMP, is a one-step nucleic acid amplification method that multiplies specific sequences of viral RNA. It is used to diagnose infectious diseases caused by viruses. RT-LAMP technology combines the LAMP single-tube technique for the amplification of DNA and DNA-detection with reverse transcription, making cDNA from RNA before running the reaction. It uses either two or three sets of primers and a polymerase with high strand displacement activity in addition to a replication activity.

The RT-LAMP was invented in the early 2000s’ and has since been successfully developed and utilized in specific assays for the detection of HIV-1 virus[1], the Ebola virus[2], and the West Nile virus[3]. More recently, this technology was adapted for the detection of COVID-19’s viral RNA in a step that offers significant advantages over the current “gold standard.”[4]

RT-LAMP technology has all the necessary characteristics to position itself as the answer to the growing global need to expand COVID-19 testing capacity while bringing diagnostic infrastructure closer to patients in need.

RT-LAMP vs. RT-PCR: improved accuracy with simpler and more efficient operation

RT-PCR test includes modulated heating and cooling throughout the processing cycle, that requires precise temperature control and a costly thermal cycler.  In contrast, in RT-LAMP technology the RNA amplification is done at a constant temperature (isothermal) so that an expensive thermal cycler is not required. Moreover, this difference in the processing method also enables a much shorter detection time for RT-LAMP technology (approximately 20 minutes), compared to several hours for RT-PCR due to the fact that there is no need to wait for multiple thermal changes.

Similar to RT-PCR, RT-LAMP technology is an extremely reliable molecular detection method with high sensitivity and specificity. Unlike RT-PCR, RT-LAMP’s high specificity is achieved by recognizing the target sequence using six independent sequences at the start and four independent sequences towards the latter stages of detection. Some studies have found RT-LAMP to be much more sensitive than normal RT-PCR assays, exhibiting higher specificity, with no false-positive results reported.[5] [6]

While in RT-PCR the testing usually requires large, complex, and costly lab equipment, RT-LAMP enables a much simpler and more cost-efficient detection process. Performing RT-PCR testing is usually more complicated and as a result requires extensive and costly training of specialized personnel, while RT-LAMP allows for a simple process with minimal training needed for operators. Moreover, in RT-LAMP, primer recognition of the target gene leads to a strong colorimetric reaction, which allows for detection without highly specialized or costly instrumentation but rather through clear and easy-to-interpret visual results.

RT-LAMP enables fast, simple, and accurate COVID-19 testing, ideal for near-patient applications, such as airports, educational facilities, workplaces etc.

RT-LAMP: an ideal solution to meet a growing global need

In a final analysis, RT-LAMP technology is an accurate, rapid, cost-efficient, and easy-to-operate molecular diagnostic method that may be an ideal solution for viral diagnosis of COVID-19 and others at the point-of-care. RT-LAMP technology has all the necessary characteristics to position itself as the answer to the growing global need to expand COVID-19 testing capacity while bringing diagnostic infrastructure closer to patients in need. Its speed, simplicity and low price single out the RT-LAMP method as the preferred diagnostic approach for assisting governments in their mission to return their countries back to a state of social and economic normalcy.

[1] Viet Loan Dao Thi, et al., (2020), A colorimetric RT-LAMP assay and LAMP-sequencing for detecting SARS-CoV-2 RNA in clinical samples

[2] Wei E. Huang, et al., (2020), RT-LAMP for rapid diagnosis of coronavirus SARS-CoV-2

[1] Kelly A.Curtis, Donna L.Rudolph, S. Michele Owen, (2008), Rapid detection of HIV-1 by reverse-transcription, loop-mediated isothermal amplification (RT-LAMP)

[2] Patricia Lam Orcid, Ruth A. Keri, and Nicole F. Steinmetz, (2017), A Bioengineered Positive Control for Rapid Detection of the Ebola Virus by Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP)

[3] Manmohan Parida, Guillermo Posadas, Shingo Inoue, Futoshi Hasebe, and Kouichi Morita, (2020), Real-Time Reverse Transcription Loop-Mediated Isothermal Amplification for Rapid Detection of West Nile Virus

[4] Weihua Yang, Xiaofei Dang, Qingxi Wang, Mingjie Xu, Qianqian Zhao, Yunying Zhou, Huailong Zhao, Li Wang, Yihui Xu, Jun Wang, Shuyi Han, Min Wang, Fenyan Pei, Yunshan Wan, (2020), Rapid Detection of SARS-CoV-2 Using Reverse transcription RT-LAMP method

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