Molecular Characterization of Transcriptome-wide Interactions between Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and Porcine Alveolar Macrophages in vivo

Zhou, Ping; Zhai, Shanli; Zhou, Xiang; Lin, Ping; Jiang, Tengfei; Hu, Xueying; Jiang, Yunbo; Wu, Bin; Zhang, Qingde; Xu, Xuewen; Li, Jin-ping; Liu, Bang

For viremia detection, serum samples were collected daily from all pigs. Total viral RNA was extracted from 200 μl serum using TRIzol Reagent (Invitrogen, Carlsbad, CA). cDNA was synthesized using oligo(dT)15 primer, M-MLV Reverse Transcriptase (Promega, Madison, WI) in 50 μl reaction mixture according to the manufacturer's instructions. Absolute quantitative-PCR (Q-PCR) was performed using primers specific to the ORF7 of PRRSV (sense: 5'-TCA GCT GTG CCA AAT GCT GG-3'; antisense: 5'-AAA TGG GGC TTC TCC GGG TTT T-3'). For absolute quantification, the pET-18M plasmid of the known copy number containing the ORF7 fragment generated standard curve. Viral copies per ml of the unknown samples were determined by linear extrapolation of the Ct value plotted against the standard curve [14] .