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What is a PCR Test?

Polymerase Chain Reaction (PCR) tests are used for diagnosing infectious diseases such as COVID and genetic changes. The tests work by identifying the DNA or RNA of the virus or pathogen (disease-causing organism) or abnormal cells in a given sample.

Benefits of the PCR Test

These tests are highly accurate and can identify the disease at an early stage when there are only a few pathogens present and hardly any symptoms.

How is the PCR Test performed?

  • A sample of mucus, saliva, blood, urine, or tissue is obtained and placed in a PCR machine. The sample may be obtained by a nasal swab or collecting blood from a vein in your arm.
  • A special enzyme known as a polymerase is added to the sample.
  • The polymerase triggers a chain reaction which makes billions of copies of specific DNA fragments within the sample in about an hour.
  • Certain viruses, such as the COVID-19 virus, are made up of RNA and need to be first converted to DNA before the chain reaction is initiated. This is known as reverse transcription PCR or rtPCR.
  • The pathogen or virus can be easily identified based on the presence of the amplified genetic material.