Quantitative TaqMan real-time PCR for detection of porcine reproductive and respiratory syndrome virus

A TaqMan-based real-time PCR assay was developed to rapidly detect the porcine reproductive and respiratory syndrome virus(PRRSV).Primers and probe specific to the conserved region of the PRRSV N gene were selected,and the reactive system and conditions were optimized to improve the sensitivity,specificity and repetition of the assay.The results showed that the real-time PCR assay was specific and there were no cross reactions with other common porcine viruses. The sensitivity of the assay was 1.2×101copy/ml of plasmid coding partial PRRSV N gene,which is 100 times higher than conventional PCR.It took no more than three hours from viral RNA extraction to complete the real-time PCR,and the assay was simple and had good repeats.Among tissue samples of 48 clinical diseased pigs,29 were confirmed PRRSV infected by real-time PCR,in which only 19 were confirmed by conventional PCR.This TaqMan-based real-time PCR assay is a specific,sensitive and quick tool suitable for early and quick detection of PRRSV in clinical labs.