The principle of African swine fever detection instrument - real-time fluorescence quantitative PCR instrument: Polymerase chain reaction (PCR) is a molecular biology technology used to amplify specific DNA fragments. It can be seen as a special DNA amplification in vitro, consisting of several steps such as high-temperature denaturation, low-temperature annealing, ａnd warm extension to form a temperature cycle, allowing the target gene to be rapidly amplified. It has strong specificity, high sensitivity, simple operation, ａnd time-saving characteristics, ａnd is a major innovation in gene amplification technology. PCR technology can specifically amplify trace amounts of target DNA by millions of times, greatly improving the analysis ａnd detection capabilities of DNA molecules.