No need. Pcr is the abbreviation of polymerase chain reaction, which is a molecular biology technique to amplify specific DNA fragments. It can be regarded as a special kind of DNA replication in vitro. In 2022 1 1, there is no need to go to Dalian airport in Japan. The biggest feature of PCR is that it can greatly increase the amount of DNA. PCR has the characteristics of strong specificity, high sensitivity, simplicity, rapidity and low purity requirements.