RT-PCR Test

The world is on the verge of a halt again, as the new Omicron variant of Covid-19 emerged in late November in South Africa, spreading slowly in many countries so far, which resulted in the nations re-establishing their travel guidelines for other countries.

As unimaginable times of uncertainty looms large ahead, at present, the situation has thrown the medical fraternity on its toes as this variant, allegedly, contains severe mutations and can change the entire course of the covid-19 pandemic. The news, however, has been emerging from the Omnicron-affected community across the nations that the symptoms are not severe like previous covid-19 variants, which may also be a consequence of vaccinations and boosters. Still, the sheer number at which the spread is taking place, no wonder this variant can engulf the entire world in less time than SARS-Cov2 impacted since November 2019.

With plenty of questions arising in front of health officials and guards of humanity, the most important one today is, if the RT-PCR test (a test used worldwide to detect coronavirus) will be able to identify the Omicron variant effectively or not. The article tries to answer this question, but first, let’s know all about RT-PCR and how it works.

What is an RT-PCR test?

The reverse transcription-polymerase chain reaction (RT-PCR) test is a nucleic acid-based test that is considered the gold standard to detect coronavirus and is used globally. The test aims to look for the genetic material of the virus that will help determine its presence and viral load in the body. A conventional PCR test takes about 6-8 hours to give the results. These days, the rapid RT-PCR test is used by almost all countries as it provides the outcome within a few hours.

What is a virus and its genetic material?

Every living organism like humans, animals, viruses, and pathogens contain a genetic material that holds genetic code or blueprints of how these organisms are made. A virus is also a microscopic bundle of genetic material. This genetic material can be of two types – DNA or RNA.

Viruses like covid-19 causing coronavirus (SARS-CoV-2) only contain RNA.

What are DNA and RNA?

Deoxyribonucleic acid (DNA) is a two-strand molecule that holds all the information of how the organism is made. Whereas Ribonucleic acid (RNA) is a single strand molecule that copies and transmits the parts of the information to proteins in the body so they can keep the body functioning and developing.

As the SARS-CoV-2 contains only RNA, reverse transcription is necessary through a specific enzyme that converts RNA into DNA as only DNA can be copied. Here, the question may arise, ‘why do we need to copy DNA?’ Read on to know.

How does the RT-PCR test detect the virus?

The main idea behind the RT-PCR test is to copy and increase the targeted transcribed viral DNA in the infected person’s body to capture the presence of a virus. Increasing is vital instead of spotting the minute virus amongst huge genetic information. And that is why copying DNA is essential.

The nasal and throat samples are collected as these are the areas where the virus initially gathers. The sample is mixed with a certain chemical to remove everything else and capture the RNA aspect, which may or may not contain the virus’s RNA along with the person’s own. Immediately, this RNA is converted or reverse transcribed to DNA. Now, additional complementing DNA is added to it so they get attached to transcribed viral DNA.

After placing this mixture in an RT-PCR machine, where a chemical reaction takes place that increases the number of DNA strands and creates thousands of copies. Further, a fluorescent dye is released into the mixture that gets attached to the marker labels or spike protein through which the virus enters into human cells. It helps determine the viral load in the computer screen after each cycle of creating more DNA copies. The lesser the number of cycles reaching a fixed fluorescent level, the more the severity of viral load.

Thus, RT-PCR tests are highly reliable and continue to be the most accurate way available for detecting coronavirus.

Can RT-PCR effectively identify the Omicron variant?

As the RT-PCR tests target the different mutations and more than one spike in protein to ensure accuracy, it is seen that with Omicron, a certain mutation was not getting captured. With the following research, the World Health Organization (WHO) presented that a phenomenon called S gene dropout or failure is noticed, and if it is used as a marker for this variant with more genome sequencing results, no omicron virus can escape the RT-PCR test results.

Presently, with RT-PCR tests targeting all three genes, most diagnostic centers are able to detect the presence of the Omicron variant completely.

In case you are planning to get yourself or your loved one tested, choose a renowned diagnostic lab, for instance, SpiceHealth. SpiceHealth’s RT-PCR test can be booked online easily. Their RT-PCT test cost in Delhi is as low as INR 299*.