What Is the Difference Between RT-PCR and Rapid PCR?

Coronavirus disease 2019 or COVID-19 is a respiratory illness caused by the SARS-CoV-2 virus. Various tests can detect SARS-CoV-2 infection.

The reverse transcriptase polymerase chain reaction (RT-PCR) test is the most popular and reliable diagnostic test to identify SARS-CoV-2 infection. RT-PCR assays use the PCR method to amplify particular viral RNA (ribonucleic acid) segments.

This test is very sensitive and specific because it can find even minute levels of the viral RNA in a clinical sample. RT-PCR tests can track the efficacy of treatment for COVID-19.

Other tests that can detect SARS-CoV-2 include:

• Antigen tests
  • Detect the presence of SARS-CoV-2 in clinical samples.
  • Can detect proteins on the surface of the virus.
  • Generally, less sensitive than RT-PCR tests.
  • Typically used to diagnose active infections, but they may not detect the virus in the early stages of infection or asymptomatic people.
• Antibody tests
  • Also called serological tests and detect the presence of antibodies in the blood that is produced in response to SARS-CoV-2 infection.
  • Can determine whether a person has been infected with the virus in the past.
  • Are not typically used to diagnose active infections.

Reverse transcriptase polymerase chain reaction (RT-PCR) involves the reverse transcription of RNA into DNA, which is then amplified using polymerase chain reaction (PCR).

RT-PCR tests are highly sensitive and specific, and they can be used to detect even small amounts of RNA from a virus in a clinical sample.

The RT-PCR test involves several steps, including:

• Sample preparation: A sample of bodily fluid (such as saliva or nasal secretions) is collected, and the RNA is extracted from the sample.
• Reverse transcription: The RNA is converted into a complementary DNA (cDNA) molecule using an enzyme called reverse transcriptase.
• PCR amplification:
  • The cDNA is amplified using the PCR technique.
  • Involves the use of special enzymes and reaction conditions to make multiple copies of the target DNA sequence.
• Detection: The amplified DNA is then detected using a variety of techniques, such as gel electrophoresis or fluorescence-based assays.

Reverse transcriptase polymerase chain reaction (RT-PCR) is a versatile and powerful laboratory technique. It is widely used in several clinical and research settings.

• Diagnosis of infectious diseases
  • RT-PCR detects the presence of viruses, bacteria, and other microorganisms in clinical samples.
  • Commonly used to diagnose COVID-19, influenza, and tuberculosis.
• Genetic testing
  • RT-PCR detects genetic mutations or abnormalities in samples of DNA or RNA.
  • Commonly used in cancer diagnosis and to identify genetic disorders.
• Monitoring treatment
  • Monitor the effectiveness of treatment for viral infections, such as HIV and hepatitis.
  • Used to monitor the levels of therapeutic proteins in the blood.
• Quality control
  • Help ensure the quality and purity of the final product in the production of pharmaceuticals and biologics.

Rapid polymerase chain reaction (PCR) is a variation of the PCR technique that uses specialized enzymes and reaction conditions to amplify DNA quicker than standard PCR. Though rapid PCR reduces the time required for the amplification process, it may have lower sensitivity or accuracy compared to standard PCR.

Rapid PCR tests are highly sensitive and specific, and they can be used to detect even small amounts of DNA in a sample.

The rapid PCR test involves several steps, including:

• Sample preparation: A sample of DNA is collected and extracted.
• PCR amplification:
  • The DNA is amplified using the PCR technique. 
  • Special enzymes and reaction conditions help make multiple copies of the target DNA sequence.
• Detection: The amplified DNA is then detected using several techniques, such as gel electrophoresis or fluorescence-based assays.

Rapid polymerase chain reaction (PCR) is a powerful and fast technique. It has various applications and can detect genetic abnormalities. It is commonly used in the following conditions:

• Forensics:
  • Helps identify individuals based on their DNA.
  • Commonly used in criminal investigations, paternity testing, and the identification of missing persons.
• Identification of genetically modified organisms: Can detect the presence of genetically modified DNA in food products and environmental samples.
• Detection of genetic abnormalities:
  • Detects genetic mutations or abnormalities in samples of DNA.
  • Commonly used in the diagnosis of genetic disorders and cancer.
• Research: Used in the study of gene expression, regulation, and function.
• Quality control: Used in the production of pharmaceuticals and biologics to ensure the quality and purity of the final product.