In the fight against Covid-19, India has come up with medical interventions in the form of vaccines but there is a strong need for rapid, specific and sensitive SARS-CoV-2 detection technology to prevent the virus from spreading. Aligning with this, a cost-effective and sensitive RT-LAMP technology has been developed for rapid diagnosis of Covid-19.
Indian Council of Medical Research (ICMR) and National Institute of Virology (NIV), Pune have jointly developed the RT-LAMP kits for which the technology has been transferred to two companies for the manufacturing of these kits.
RT-LAMP: A new technology for detecting the virus
The current and widely used method for diagnosis of Covid-19 is the RT-PCR test which detects the presence of viral nucleic acids in nasopharyngeal swab samples. There are certain shortcomings with the RT-PCR tests, as the specificity and sensitivity of the test is about 95% and the turnaround time is about 10 hours so that the result will be available only by the next day. Hence, a superior technique to accurately and timely detect the virus is now in India in the form of RT-LAMP (Reverse Transcriptase loop-mediated isothermal amplification) technology.
RT-LAMP detects viral RNA and allows for quicker analysis of genetic material than traditional PCR. According to ICMR, the results through RT-LAMP technology can be detected visually and no other sophisticated instruments are required for the interpretation of results.
Science Behind: How Does RT-LAMP Technology work?
The methodology for RT-LAMP is a one-stop nucleic acid amplification. Unlike other technologies, RT-LAMP recognizes and multiplies specific sequences of RNA of the SARS-CoV-2. The mechanism works by making a copy of RNA into cDNA (copy DNA) by the usual method of reverse transcription and then the DNA is amplified by the LAMP technique.
The prime feature of RT-LAMP is that it can achieve high specificity due to the target sequences. It uses six independent sequences at the start and four independent sequences towards the latter stages. Hence, recognition of the target genome leads to a strong colourimetric reaction, which provides for the early detection of viruses without highly specialized or costly instrumentation.
RT-LAMP technology: A superior option for detection
The LAMP technology has many advantages over RT-PCR technology, especially in regards to thermal cycles. While the RT-PCR test needs different temperatures in one cycle, the RT-LAMP technology is done at a constant temperature cycle, that is, 65°C, which removes the requirements for a thermal cycler.
Other benefits of the technology include higher amplification efficiency as there is no need to wait for thermal changes as against a traditional PCR which can take around 3 to 4 hours. But an RT-LAMP test takes less than an hour, making it highly sensitive and cost-efficient.
An equally important advantage of the LAMP technology is that the reagents can be stored at 4°C (ordinary fridge), whereas the PCR-based reagents are stored and transported in deep freezers that escalate the cost.
Covid-19: User-Friendly RT-LAMP kits
The World Health Organization (WHO) has urgently demanded an extension of screening and testing. With this, to address the Covid-19 pandemic, an accurate, low-cost and user-friendly diagnostic method is the need of the hour, and so, RT-LAMP is ideal for the nation’s requirements and conditions. There is an urgent need to build the testing capacity of India against what has been achieved with the available interventions. The RT-LAMP method’s speed and simplicity allow it to be the ideal method for diagnosing the infection.