The research on nucleic acid has a history of 100 years. In the late 1960s and early 1970s, people devoted themselves to the study of gene isolation in vitro. In 197 1, Korana first put forward the idea of nucleic acid amplification in vitro: "After DNA denaturation, use appropriate primers to hybridize, use DNA polymerase to extend the primers, and repeat this process, then the tRNA gene can be cloned".
1983 One day, American scientist Kary Mulis was driving on the winding interstate highway, and the prototype of PCR technology was born. He proved the idea of PCR in experiments, applied for the first patent on PCR in 1985, and published the first academic paper on PCR in Science magazine. Since then, PCR technology has been widely recognized by the life science community, and Kary Mulis won the Nobel Prize in chemistry from 65438 to 0993. The DNA polymerase originally used by Mullis is Klenow fragment of Escherichia coli DNA polymerase I, but its disadvantage is that the enzyme is not resistant to high temperature and will be denatured and inactivated at 90℃, so it needs to be added again every cycle. In 1988, Saiki et al. extracted a thermostable DNA polymerase from an aquatic thermophilic bacterium isolated from a hot spring, which overcame this shortcoming, thus making PCR technology widely used and making PCR the basic cornerstone of genetic and molecular analysis.
After more than ten years of development, PCR has become a routine technology in the laboratory. It is an indispensable means in modern molecular biology research and an extremely sensitive amplification system. Compared with traditional clinical diagnosis methods, nucleic acid diagnosis is a molecular diagnosis technology, which can make up for some defects of traditional clinical diagnosis methods. For example, nucleic acid diagnosis can directly reveal the existence of pathogens, objectively reflect the infection and activities of pathogens in the human body, and can be used as an effective monitoring means in clinical treatment. In addition, nucleic acid diagnosis technology can also detect pathogens that are difficult to detect by conventional detection methods, such as overcoming the window period from infection to antibody production in enzyme immunoassay technology. Therefore, the nucleic acid diagnosis technology represented by PCR technology has been widely used in clinical diagnosis.