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

© 2019 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

Rapid detection of tetracycline residues at clinically relevant levels via a novel, inexpensive and analytically-sensitive magneto-immunoassay – A feasibility study

Expensive, time-consuming and labour-intensive solvent-extraction and liquid-chromatography methods are the industry's current gold standard for antibiotic residue quantification. A novel immunoassay methodology and system for the rapid detection of clinically relevant levels of tetracycline residues found in food-producing animal tissues is described. Anti-tetracycline antibody-coated paramagnetic particles were used for the specific capture of tetracycline in spiked buffer (with and without a 1% pork muscle tissue suspension) and quantified via an analytically-sensitive in-house magnetometer instrument. Detection of tetracycline between 0.1 μg/mL - 1 μg/mL was achieved, with a readout time (including sample treatment) presented in 20 min. The magneto-immunoassay described provides a rapid, low-cost, de-skilled and analytically-sensitive solution for tetracycline screening at the point-of-sampling, with potential applications for other prevalent antibiotic families used in the international farming and food industry