Principle and application of PCR reaction

PCR, also known as polymerase chain reaction, is a technique to amplify nucleic acids in vitro (test tube, slice …). This technology simulates the replication process of natural DNA in the body. Its basic principle is an enzymatic synthesis reaction that specifically amplifies DNA fragments between two known sequences in the presence of templates, primers, four dNTP and Laire DNA polymerases. Each cycle includes three steps: high temperature denaturation, low temperature annealing and medium temperature extension. The products in each cycle are used as templates for the next cycle. After 30 cycles, the new DNA fragment between the two primers theoretically reached 230 copies (about 109 molecule). The specificity of PCR technology depends on the specificity of primer binding to template.

PCR technology is widely used in the diagnosis of hereditary diseases, the detection of infectious disease pathogens, forensic medicine, archaeology and molecular biology.