RT-PCR (real time – reverse transcription polymerase chain reaction)

A  molecular test used to determine if a person is infected with a virus like the SARS-CoV-2 virus. The test can also be used to diagnose genetic diseases.

It is a genetic test that detects the RNA of the virus. It works for a person who is currently sick or symptomatic, asymptomatic, or presymptomatic.

SARS-CoV-2 causes respiratory disease and infects the upper and lower respiratory tract through the eyes, nose, and mouth. The test, therefore, requires taking specimens with a swab from the nose and throat of a person who may be infected. The swab with the specimen is put in a sterile container and sent to a laboratory. Most molecular test swabs must be kept within a certain temperature range so that the test will be accurate. The sample must arrive at the lab within 72 hours. A lab technician mixes liquids with the swab to extract the genetic material of any virus that may be on the swab. The lab technician uses special reagents, called primers and probes, and a high-tech machine to conduct several controlled heating and cooling cycles to convert the virus’s RNA into DNA, and then make millions of copies of the DNA. Some tests use only one warming cycle to make copies of the DNA. When specific probes bind to DNA, a special type of light is produced that can be seen by the machine and the test shows a “positive” result for infection with SARS-CoV-2, the virus that causes COVID-19. The laboratory-based work takes between two to four hours to get a result.

Positive results do not rule out a bacterial infection or co-infection with other viruses. Negative results do not rule out SARS-CoV-2 infection and shouldn’t be used as the only basis for patient management decisions.

Testing with the COVID-19 RT-PCR test is intended for use by clinical laboratory personnel specifically instructed and trained in the techniques of real-time PCR and in vitro diagnostic procedures.



Infectious Disease Symptoms Tests


RNA (Ribonucleic Acid)VirusAsymptomaticPresymptomaticSARS-CoV-2Respiratory tractRespiratory diseaseSwabCOVID-19DNA (Deoxyribonucleic Acid)Bacteria (singular: bacterium)