WHY IN NEWS?
- The US scientists have invented a new COVID-19 Saliva Testing method called SPOT. SPOT is Scalable and Portable Testing.
- SPOT was invented by a research team from the Carle Illinois College of Medicine. The SPOT gives COVID-19 test results in thirty minutes. The cost of the device is 78 USD. Apart from these the reagents and other testing devices are estimated to cost 6 to 7 USD. The device can be operated by anyone with minimal training.
- The test is very much similar to that of the RT-PCR. But it uses Reverse Transcriptase Loop Mediated Isothermal Amplification (RT-LAMP). However, it does not need complex machinery or expertise. It can be completed quickly and is more accurate.
RT-Loop Mediated Isothermal Amplification
- RT-LAMP is a one-step nucleic acid amplification method. It is used to multiply specific sequences of RNA. This technology is considered as an alternate to RT-PCR as it is much cheaper and easier. RT-LAMP test first makes DNA from the RNA samples. This conversion is made by reverse transcriptase enzyme. This DNA is called cDNA. Now this cDNA will be amplified for virus detection.
- The only difference between RT-PCR and RT-LAMP is that RT-LAMP uses four LAMP Primers. Primers are short fragments of nucleic acids.
- The researchers tested 104 clinical samples using SPOT. Of these it accurately identified twenty eight of thirty COVID-19 positive samples and 73 out of 74 COVID-19 negative samples.
About new COVID-19 tests
- Every day ten to fifteen new COVID-19 tests are launched in the market. These tests claim to be quick. However, none of these quick antigen tests are reliable as that of RT-PCR.