Initial trail results of a magnetic biosensor for the rapid detection of Porcine Reproductive and Respiratory Virus (PRRSV) infection

Abstract

The resonant coil magnetometer quantifies paramagnetic particles (PMPs) and has been used to develop magneto-immunoassays in a range of formats. The advantage of magneto-immunoassays is that they are relatively inexpensive, portable, easy to perform and give results in under 5 min. Porcine Reproductive and Respiratory Virus (PRRSV) is an infection of domesticated pigs producing large economic losses in the swine industry current diagnosis is performed using commercially available ELISA kits. Here we describe the development of a competitive magneto-immunoassay (MIA) and pilot study with porcine serum samples. The data show that this technology has the potential for use as a rapid and portable in field system for the detection of antibodies in porcine serum to PRRSV. A range of assay parameters and magnetometer settings were optimised, including the concentration of antibody conjugated PMPs used in the assay and movement of an external magnet to pull particles to a sensor surface. PRRSV positive control serum demonstrated competition with antibody conjugated PMPs with a dose dependent relationship. The magneto-immunoassay developed showed good agreement with the PRRS IDEXX X3 ELISA. The PRRSV magneto-immunoassay demonstrated a sensitivity of 73% and specificity of 100%. The results suggest that a rapid assay using the magnetometer technology detects specific anti-PRRSV antibody in pig serum. The magneto-immunoassay is suitable for use as a rapid ‘on-site’ method for the serological detection of PRRSV infection. Keywords: Porcine Reproductive and Respiratory virus, Resonant Coil Magnetometer, Magneto-immunoassay, Competitive immunoassay, Serology, Pig serum