Understanding PCR Tests

Polymerase chain reaction (PCR) test is considered a quick and accurate way to diagnose genetic changes and infectious disease. People searching for a “PCR test near me” online also use other terms to look for the test including rtPCR, qPCR, real-time PCR, quantitative PCR, reverse transcription PCR, and polymerase chain reaction.

A PCR test involves finding the RNA or the DNA of the organism causing the condition (also known as pathogen). A PCR test is also done to look for abnormal cells in the sample. Most pathogens and viruses contain RNA or DNA. A PCR test can also help find evidence of a condition during the infection’s early stages.

Other tests can miss the early stages of certain conditions because there’s not enough bacteria, viruses, or pathogens found in the sample. Another possible reason is the body has not had sufficient time to develop an antibody response. Antibodies refer to the proteins that are created by the immune system.

Antibodies also work by attacking bacteria, viruses, and other foreign substances. PCR tests can also be used to detect certain conditions even if there is only a small amount of pathogens in the body. During a PCR test, a small amount of the genetic material found in the sample is copied countless times.

This copying process is referred to as amplification. When there are pathogens found in the sample, the amplification process will make them a lot easier to see. Essentially, PCR tests are done to:

  • Find very small amounts of cancer cells that were not detected in other test types
  • Diagnose some infectious conditions
  • Determine the genetic changes that can cause certain conditions to develop

How PCR Tests Work

Here’s how a PCR test works:

  • A sample of the saliva, tissue, mucus, saliva and blood will be taken.
  • The sample contains the person’s DNA or the DNA of a cancer cell or other sample pathogen.
  • The sample will be placed in a special machine. An enzyme known as polymerase will be added to the sample. This will enable the sample to produce multiple copies.
  • The process of copying will be repeated countless times. In an hour, billions of copies will be made. If a pathogen or virus is present, it will be indicated in the machine.

Some viruses, including the COVID-19 machine will be made up of DNA instead of RNA. In similar cases, the RNA needs to be changed into DNA before it is copied. The process of turning RNA into DNA is known as reverse transcription PCR (rtPCR).

What to Expect During a PCR Test

While there are various ways to get a PCR test sample, two of the most common methods are nasal swabs and blood tests.

Blood Test

During a blood test, a blood sample from the vein in the arm will be taken using a small needle. After insertion, a small amount of blood is collected and placed in a vial or test tube. Some people will feel a little sting during the process of collecting blood. Fortunately, the process will not take more than five minutes.

Nasal Swab

A nasal swab will be taken from the anterior nares or the front part of the nostrils. There’s an option to also take it from the back of the nostrils. This process is also known as nasal mid-turbinate or NMT swab. Samples can also be taken from the nasopharynx or the nose and throat’s uppermost part.

PCR Test Risks

A blood test has very minimal risk. A slight bruising or pain may be felt at the spot but most of the symptoms will go away quickly. A nasal swab on the other hand might tickle or cause the patient to cough. Gagging or coughing are two of the most common side effects of nasopharyngeal swab.

PCR tests have become quickly popular recently with the COVID-19 pandemic, and were used to diagnose active or previous infections. If you require one to be done for diagnostic purposes or for pre-departure screening, do not hesitate to look up “PCR test near me”.