As the COVID-19 coronavirus spreads around the world, the IAEA, in collaboration with the Food and Agriculture Organization of the United Nations (FAO), is offering its support and expertise to assist countries in using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), one of the most accurate laboratory methods for detecting, tracking, and studying the COVID-19 coronavirus.
But what exactly is real-time RT-PCR? What distinguishes it from PCR?
What is RT-PCR?
Real-time reverse transcription polymerase chain reaction (RT-PCR) is a nuclear-derived technology for identifying the presence of particular genetic material in any disease, including viruses. Originally, radioactive isotope markers were employed to detect specific genetic components, but later refinement has resulted in the substitution of isotopic labeling with unique markers, most often fluorescent dyes. Unlike traditional RT-PCR, which only reveals data after the process, this technology allows scientists to examine the results practically instantly while the process is still running.
What is a virus? What is genetic material?
A virus is a small genetic cargo encased in a molecular envelope. This genetic material can take the form of either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) (RNA).
DNA is a two-strand molecule present in all species, including animals, plants, and viruses, that contains the genetic code, or blueprint, for how these organisms are created and grow.
RNA is a one-stranded molecule that copies transcribe, and communicates sections of the genetic code to proteins, allowing them to synthesize and perform activities that keep organisms alive and evolving. RNA variants are responsible for copying, transcribing, and transmitting.
Some viruses, such as the coronavirus (SARS-CoV-2) that causes COVID-19, only contain RNA, which means they must proliferate and live by invading healthy cells. Once inside the cell, the virus utilizes its genetic code — RNA in the case of the COVID-19 virus — to seize control and reprogram the cells, transforming them into virus-producing factories.
Why should you utilize real-time RT-PCR?
The real-time RT-PCR technology is very sensitive and specific, and it may provide a valid diagnosis in as little as three hours, while laboratories often require six to eight hours. Real-time RT-PCR is substantially faster than other known viral isolation technologies and has a lesser risk of contamination or mistakes because the entire process may be carried out within a closed tube. It is still the most accurate approach known for detecting the COVID-19 virus.
What exactly is PCR, and how does it vary from real-time RT-PCR?
RT-PCR is a kind of polymerase chain reaction (PCR). The two procedures employ the identical mechanism, with the exception that RT-PCR includes a reverse transcription of RNA to DNA, or RT, step to allow for amplification. This implies that PCR is used for pathogens that already have DNA for amplification, such as viruses and bacteria, but RT-PCR is used for pathogens that have RNA that has to be transcribed to DNA for amplification.
PCR is one of the most extensively used diagnostic procedures for identifying pathogens such as viruses that cause illnesses such as Ebola and African swine fever. Because the COVID-19 virus only includes RNA, it is detected using real-time or traditional RT-PCR.