Piezoelectric quartz crystal based screening test for porcine reproductiveand respiratory syndrome virus infection in pigs

A piezoelectric quartz crystal (PQC) based screening test for porcine repro ductive and respiratory syndrome virus (PRRSV) infection in pigs is describ ed. Gold-coated quartz crystals (10 MHz) were pre-modified by recombinant P RRSV protein. A direct assay format was employed to detect the presence of anti-PRRSV antibody in pig serum. Both dip and dry detection methods and st atic liquid-phase measurement approaches were adopted to perform the screen ing test and real time monitoring of molecule binding. Once the surface had been modified with antigen protein, only one sample incubation step of 5 m in duration was required to provide frequency changes corresponding to the binding of the target antibodies. Serum samples from PRRSV infected pigs pr oduced significant binding with the signal ranging from. 100 to 400 Hz depe nding on the different titer, whereas samples from uninfected pigs produced no or minimal frequency changes of 0-60 Hz. The proposed PQC sensor can be used to screen pigs suspected to have been infected with PRRSV and to prov ide 'yes' or 'no' results. A total of 41 sera were detected. The results ag reed well with those from licensed immunoassay.