Establishment of a Real-time Fluorescent Recombinase Polymerase Amplification (RPA) for the Detection of African Swine Fever Virus

African swine fever (ASF), which caused by African swine fever virus (ASFV), is an acute, highly contagious disease characterized by high fever. It leads to serious economic losses in pig industry. 3 assemblies of primers and probes targeting were designed to amplify ASFV B646L (p72) gene using recombinase polymerase amplification (RPA) technology. The Real-time fluorescent RPA method was established after screening of primers and probes, optimization of reaction conditions, tests of sensitivity, specificity and repeatability. The results showed that the method could detect 10 copies of DNA within 20 min at 39℃. No cross-reaction was found when testing swine fever virus, porcine circovirus type 2, porcine parvovirus, pseudorabies virus. According to the fluorescence intensity from 5.5×10⁶ to 5.5×10⁰ copies/μL at each time point, the coefficient of variation was 0.38% to 28.30%. In conclusion, this method could be used for the qualitative detection of ASFV pathogen, which might provide technical support for the early diagnosis of ASFV infection in China, and was also of great significance for the development of corresponding control measures.