Magnetic particle-linked anti hCG β antibody for immunoassay of human chorionic gonadotropin (hCG), potential application to early pregnancy diagnosis

The objective of this study was to develop a magnetic particle-linked monoclonal antibody to hCG β for immunosorbent assay of human chorionic gonadotropin (hCG) with improved detection sensitivity. Monoclonal antibody against hCG β was found to be optimally cross-linked to the superparamagnetic particles (SPIO) using EDC and NHS as cross-linking reagents. This superparamagnetic particle-linked monoclonal antibody was able to concentrate hCG from a tested solution for further ELISA assay using horse radish peroxidase-labeled monoclonal antibody against hCG β. This hybrid technique had greatly decreased the detection limit to 0.1 mIU/mL, making an early detection of pregnancy possible. With an improved sensitivity and simple operation, the magnetic particle-linked anti hCG β antibody for immunoassay of human chorionic gonadotropin (hCG) has a great potential to supersede the traditional ELISA for pregnancy diagnosis.

► Superparamagnetic iron oxide (SPIO) as magnetic supports to form immunomagnetic particles (IMP).
► Antibody against β subunit of human chorionic gonadotropin hormone (Anti hCG β antibody) is crossed linked to SPIO.
► The SPIO-anti hCG β concentrates hCG in an analyst under an external magnetic field.
► Horse radish peroxidase-labeled anti hCG β subunit is used to run ELISA for the captured hCG.
► The SPIO-ELISA assay improves hCG detection sensitivity to 0. 1 mIU/mL.