RT-PCR Testing

What Is RT-PCR Test?

The COVID-19 RT-PCR Test is a real-time reverse transcription-polymerase chain reaction test for the detection of nucleic acid from SARS-CoV-2 by collecting nasopharyngeal or oropharyngeal swab specimens from individuals suspected of COVID-19.

This is achieved by monitoring the amplification reaction using fluorescence, a technique called quantitative PCR (qPCR).  It helps professionals to review the results on an immediate basis. The RT-PCR is one of the widely used methods for the detection of COVID-19.

RT-PCR is a laboratory technique involving reverse transcription (RT) of viral RNA into DNA and then this Complementary DNA is amplified with the help of another technique called polymerase chain reaction (PCR).  It helps to detect even a very low concentration of virus at the time by amplification of DNA even when symptoms of the disease are not visible.

How Does A Covid-19 RT-PCR Test Work?

Sample collection is done using a swab to collect respiratory material found in your nose. The RT-PCR test uses nasopharyngeal swab/oropharyngeal swabs/throat swab/nasal swab for the identification of virus particles in the patients. The test is carried out by trained professionals with the help of an RT-PCR test kit.

After collection, the swab is sealed in a tube and then sent to a covid-19 testing laboratory.  It further involves the extraction of genetic material (RNA) of the Covid-19 virus.

The PCR step then uses a PCR machine, called a thermal cycler, which amplifies the SARS-CoV-2 virus’s genetic material. During this process, one of the probes/ chemicals produces a fluorescent light if SARS-CoV-2 is present in the sample.

Who Should Get The RT-PCR Test?

If the patient experiences any one of the symptoms of coronavirus which is mainly the loss of smell or taste and difficulty in breathing, It is advisable to get the Covid-19 RT-PCR test done, in accordance with the ICMR guidelines.

The only way to counter the spread of the pandemic is to test rampantly and some companies like SpiceHealth have been innovating constantly to offer medical care, having conducted more than 3.2 million RT-PCR tests since its launch in November 2020 at the most affordable cost.

How Accurate Are RT-PCR Tests? 

RT-PCR is considered the gold standard for detecting COVID-19.  It is one of the fastest and most accurate laboratory methods for the detection of COVID-19. The real-time RT–PCR technique is highly sensitive and specific and can deliver a reliable diagnosis in about three to four hours.

According to health experts, RT-PCR tests are more accurate compared to other tests such as antigen and antibody tests. The positive test result is highly confirmatory, as a dual test is done before reporting, first at the time of screening and then for confirmation. Also, there are no side effects of the RT-PCR test. 

What Are The RT-PCR Test Protocols?

The quantification of mRNA using RT-PCR can be achieved as a one-step or a two-step reaction. The difference between the two approaches lies in the number of tubes used when performing the procedure.

In a one-step protocol, the (RT) reverse transcription and PCR components are mixed in a single tube and buffer at the same time. There is relatively less experimental variation since both reactions take place in the same tube and fewer pipetting steps reduce the risk of contamination. It is suitable for amplifying targets that are reasonably abundant.

In two-step protocols, the reverse transcription (RT) and PCR steps are performed in separate tubes and reaction conditions.

Here, a stable complementary DNA (cDNA) pool is generated and can be stored for long periods of time. Also, the genes can be amplified from the same cDNA pool without multiplexing. Due to its highly flexible priming option with different optimized buffers, it generates much better results.

How Much Time Is Required To Generate RT-PCR Results?

Many testing centers are processing a large volume of tests every day that is leading to a delay in the results. Therefore, certain companies or agencies have emerged that strive on providing these services at a faster rate.

For instance, in SpiceHealth Covid-19 testing labs.  Test results are made available within 24hours of sample collection.

What Do Covid-19 RT-PCR Test Results Mean?   

The SARS CoV2 RNA is generally detectable in nasopharyngeal/ oropharyngeal swabs during the acute phase of infection. Positive results are indicative of active infection. If your test is positive, take all the required steps, consult a  doctor, stay home and isolate yourself from others.

Negative results interpret that RNA Specific to SARS-COV-2 is not detected.  If your test is negative, continue to take preventive measures to protect yourself from getting COVID-19.

A Repeat Sample is suggested in case of clinical suspicion when the results are InconclusiveA Non Diagnostic result means that internal control is not detected, samples need to be repeated.

Does Negative Result By PCR Certifies A Complete Covid-19 Recovery?

A negative PCR test result just means that the individual is not currently affected by Covid- 19. It neither confirms recovery from COVID-19 nor confirms that the patient is no longer infectious.

About The Author:

Dinesh Mittal is a freelance Content Marketer with more than 4 years of experience in curating content and contributing to the field of Health, Psychology, Mental health, and Mental Well-being.

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