Development and application of TaqMan one-step fluorescence quantitative RT-PCR assay for detection of porcine reproductive and respiratory syndrome virus

A quantitative TaqMan one-step RT-PCR assay for detecting Porcine reproductive and respiratory syndrome virus(PRRSV) was developed using two pairs of primers based on N protein nucleotide sequence of PRRSV.This method was highly specific and did not amplify non-specific products from other swine pathogens.It could detect 10 copies of RNA at least,and was 10 to 100 fold higher sensitive than conventional RT-PCR.The method was used to determine the virus load in pig serum and showed that the immunized pigs had significantly lower virus load than control animals on the 14 days after virus challenge.