Abstract: The objective of this study is to establish an efficient and rapid real-time PCR for the detection of PRRSV NADC30-like. Specific primers were designed based on the conserved sequence of Nsp2 gene of NADC30 strain,and the optimal reaction conditions were determined by optimization,and sensitivity,specificity,reproducibility experiments and detection of clinical samples were performed. The results showed that standards at the concentration of 10⁷ copies/μL to 10² copies/μL had a fine linear relationship,and the minimum detectable concentration was 2.25×10 copies/μL. There was no cross reaction with HP-PRRSV,PCV,PEDV,TGEV,PRV,CSFV,and PoRV. All coefficient of variation（CV）of intra-groups and inter-group were < 1.9%. The detection rate was higher than normal PCR in the detection of clinical samples. In conclusion,a quantitative PCR method for the detection of PRRSV NADC30-like strain is established,which has the advantages of high sensitivity,specificity,stability,accuracy and rapid detection. It can be used for the early diagnosis of infection of PRRSV NADC30-like,as well as rapid detection and quantitative analysis of samples.

Key words: PRRSV NADC30-like, real- time PCR, Nsp2, quantitative analysis