How Polymerase Chain Reaction (PCR) is used in the diagnosis of COVID-19?

Explain how Polymerase Chain Reaction (PCR) is used in the diagnosis of COVID-19?

COVID-19:

Covid-19 is an infectious disease caused by Severe Acute Respiratory Syndrome CoronaVirus-2. First diagnosed in Wuhan China in December of 2019. Since then it has become a global pandemic.

Covid-19''s pathogen is a RNA virus. Its genome consists of Positive sense Single Stranded RNA molecule surrounded by a protein envelop. 

Diagnosis of Covid-19 by Polymerase Chain Reaction:

Polymerase Chain Reaction is one the main techniques which are used for diagnosis of Covid-19. 

Polymerase Chain Reaction:

Polymerase Chain Reaction is a Molecular Biology Technique widely used to amplify a defined segment of DNA many hundreds of thousands of times making it enough for its analysis. There are many types of PCR depending on nature of DNA template to be replicated and its use.

As we know covid-19 virus has a Positive sense RNA genome so for its diagnosis we use Reverse Transcriptase PCR for Synthesis of cDNA from viral RNA. After that we use Real Time PCR (qPCR) which monitors the amplificatuon of target DNA segments.

Diagnosis process:

Following are the steps for diagnosis of covid-19:

1. Sample collection: 

Firstly health Care provided use a swab to collect the respiratory material found in the nose. This swab is basically a narrow, long and flexible stick that goes into the nose and nasal cavity. The nasal swab collect the material from nasal cavity. After collecting the material this swab is sealed in a tube and tested.

2. Extraction:

Biomedical scientist when received the sample they isolated genetic material which is RNA in this case and separate it from the rest of the material which is present in the tube.

3. PCR:

PCR uses special chemicals, enzymes, temperature and thermocycler. Each heating and cooling cycle amplifies the amount of the target genetic material. After performing PCR many times millions of copies of SARS-CoV-2 virus will produce. An important chemical which is used in this technique produces the fluorescent light if the virus SARS-CoV-2 is present in the tube. Once amplified enough PCR machine detect these signals and scientists use special softwares to interpret the signals as a positive and negative. If the test is positive we are having Covid-19 and if the test is negative then we are safe.