A fast intraoperative PTH point-of-care assay on the Philips handheld magnotech system

BACKGROUND: Intraoperative parathyroid hormone (ioPTH) is used during minimally invasive parathyroidectomy (MIP) to predict the success of surgery and should be accurate with a short turnaround time. MATERIAL AND METHOD: We developed an ioPTH point-of-care (POC) assay on Philips handheld magnotech system. Magnotech technology is based on magnetically controlled movement of superparamagnetic nanoparticles in stationary sample fluid. During first phase, intact-PTH is captured by magnetic particles coated with anti-N-terminal-PTH antibodies. Subsequently, magnetic particles are collected by magnetic forces at sensor surface coated with anti-C-terminal-PTH antibodies. Unbound/nonspecifically bound particles are pulled away from detection surface, using a second magnetic force. Amount of specifically bound particles is measured using a surface-sensitive optical imaging technique. RESULTS: ioPTH test could be performed with a turnaround time of less than 10 min and could detect low intact-PTH concentrations (picomolar). Integrated cartridge contains a blood separation filter and dry reagents for the assay. CONCLUSION: The next magnotech ioPTH assay will be the only POC test able to give accurate results in less than 10 min, using 25 μL of whole blood. Thanks to the ease-of-use, magnotech ioPTH could be performed in the operating theater by any member of surgical staff.