Abstract: A double PCR was optimized to simultaneousely detect two pathogens of PPV and PRV. Two sets of primers were designed according to the conservative gene sequences of PPV and PRV. It was proved that the DNA samples which contained PPV and PRV could be amplified by the double PCR using the two sets of primers and it would yield two specific fragments of 942(PPV) and 485 bp(PRV).But no specific fragments were amplified from other pathogenic viruses and bacterium. The sensitive determination result indicated that as little as PPV 22 pg/L and PRV 11.7 pg/L could be detected. This method could differentiate PRV,PPV and mixed infection from the reproductive failure.

Key words: double PCR; PPV; PRV