Development of real-time fluorescent quantitative PCR assay for detection of PRRSV based on TaqMan probe

We establish a TaqMan real-time PCR assay for detection of PRRSV.The specific primers and probes were designed in the conserved region of the ORF7 gene for PRRSV,and the real-time fluorescent quantitative PCR was established by optimizing the probe concentration.Thirty clinical samples were detected by using the established quantitative RT-PCR assay,and the results were compared with that of conventional RT-PCR and viral isolation tests.TaqMan fluorescent quantitative PCR for detection of PRRSV was established successfully with the optimal probe concentration 0.4 μmol,and detection limit was as low as 3.51 copies/μl.The results by the TaqMan real-time PCR method were 100% consistent with the viral isolation tests.Sensitivity and positive rate(28/30) for clinical samples of TaqMan fluorescent quantitative PCR were relatively higher than conventional PCR(25/30).The results indicated this method has high specificity,sensitivity and reproducibility,and could be used for the diagnosis of PRRSV infection.