In 1983, an American named Mullis invented the technology of polymerase chain reaction (PCR). This technology takes advantage of the principle of DNA denaturation and renaturation, uses warm extend, heat denaturation and renaturation at low temperature, which makes DNA fragments in vitro amplification achieved. Infinitesimal amounts of target DNA can be specifically amplified millions of times, so as to improve the analysis of the DNA molecule and detection. Due to the PCR's high sensitivity and specificity, and simpleness and rapidity, this technology has become the most widely accepted technology in clinical gene amplification laboratories. At the same time, PCR technology can be divided into quantitative PCR and regular PCR, quantitative PCR is divided into real-time fluorescent quantitative PCR (RT-PCR) and digital PCR.
However, with the rapid development of PCR technology, the quality management of this technology has become increasingly prominent. How to eliminate the detection variation caused by various biological variables, and how to reduce or suppress various interference factors in experimental operation and methodology are the difficulties faced by PCR technology. For example, the novel Coronavirus nucleic acid test false negative is some practical problems faced by the technology.