PCR, the only available technique to track Covid 19?

Initially, PCR was granted to determine specific detection or production of large amounts of DNA. Human Genome Project that remarked an incredible milestone in scientific endeavors, propelled with its unique PCR based strategies. Talking about the classic PCR method on medical application, it was widely used to detect pathogens; moreover to identify criminals. Apart from Covid 19 implications, RT-PCR has become a low-cost alternative for HIV viral load monitoring technology. Moreover, PCR tests are utilized for a series of virus detections including the Hepatitis-B virus and Hepatitis-C virus.

The modified version of PCR is called Real-time PCR/ RT-PCR, enabling quantitative measurements in advance. Since December 2019, it has been a greater challenge for humankind to withstand the Covid 19 outbreak and diagnose the symptoms at early stages to stop further dispersion. PCR, as a nucleic acid detection based approach, has become a ‘gold standard’ with its high sensitivity and specificity for this case.

Schematic diagram of PCR principle

A significant attribute with the RT-PCR test is the risk of drawing out false-negative and false-positive results. Thus, this should not be considered as the only criterion for treatment and the management process of Covid 19. Genetic diversity and rapid evolution of novel coronavirus which lead to a series of mutations have become a constraint in designing RT- PCR assay with top-notch precision. For now, the diagnosis of COVID-19 basically relies on the detection of the coronavirus RNA. Unfortunately, there are several limitations associated with the suitability of PCR testing. The DNA polymerase used in PCR reaction is more prone to errors, and to design primers to generate PCR product some prior sequence information is required. Loop-mediated isothermal amplification (LAMP) was a new method developed for detecting coronavirus RNA. Notably, it requires high temperatures which limit the applicability. But it’s commendable that scientists are making continuous efforts to improve the detection of the coronavirus. They have come up with new approaches already. A protocol for detection of Covid 19 has been introduced based on SHERLOCK (Specific High Sensitivity Enzymatic Reporter Un​LOCK​ing) technique. The test can be carried out starting with synthetic COVID-19 virus RNA fragments and can be read out the output using a dipstick in less than an hour, without requiring elaborate instrumentation. However, we can still have hopes for excellent methods to be designed with this technological modifications and making this pandemic easy to handle.

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