Polymerase chain reaction (PCR) is a molecular biology technique used to amplify and amplify specific DNA fragments. High-efficiency amplification of selective fragments of genes in vitro can be used to detect target genes.

  The main principle of the PCR-fluorescent probe method is: during PCR amplification, a specific fluorescent probe is added at the same time when a pair of primers are added, the probe is an oligonucleotide, and a reporter fluorescent group is labeled at both ends. And a quenching fluorophore. When the probe is complete, the fluorescent signal emitted by the reporter group is absorbed by the quenching group; with PCR amplification, the 5 'end-3' end exonuclease activity of the Taq enzyme will degrade the probe to make the reporter fluorescent group The group and the quenching fluorescent group are separated, so that the fluorescence monitoring system can receive the fluorescent signal, that is, every time a DNA strand is amplified, a fluorescent molecule is formed, and the accumulation of the fluorescent signal and the PCR product formation are completely synchronized.