Patent ID: 8945469
Filing Date: 2015-02-03
Classification: G01N

Abstract:
1. A magnetic immunoassay system which measures a remnant magnetic signal generated from a sample for detecting an antigen contained in the sample, comprising: a nonmagnetic reaction chamber where a plurality of capturing antibodies, for binding antigens to-be-detected in the sample, are affixed to a surface of the chamber; a mechanism which moves the reaction chamber; a magnetic sensor which measures the magnetic signal from the chamber containing a mixture of the sample in a liquid state antibodies which are to bind to the antigens to be detected and further which are labeled with magnetic nanoparticles; a magnetic shield which blocks a magnetic noise in the periphery of the magnetic sensor; a magnetic field compensator comprising an electromagnet and an adjustment controller for adjusting a magnetic field applied by the electromagnet, the electromagnet configured to apply a DC magnetic field relative to a sensing direction of the magnetic sensor, the DC magnetic field being in a range between 1 nano tesla and 100 micro tesla, the adjustment controller operatively associated with the electromagnet so as to vary current through the electromagnet to thereby direct the DC magnetic field such that the first summed magnetization direction of the first group of magnetic nanoparticles binding to the first group of the antigens that are bound to the capturing antibodies is affixed indirectly to the nonmagnetic reaction chamber square with a second summed magnetization direction of (1) a second group of magnetic nanoparticles respectively bound to a second group of the antigens that are not bound to the capturing antibodies and (2) a third group of magnetic nanoparticles that are bound to neither the first group of the antigens nor the second group of the antigens; a current source which supplies an optimal DC current of a predetermined value to the electromagnet; and a processor which processes signals from the magnetic sensor to extract signals from the first group of magnetic nanoparticles binding to the first group of the antigens that are bound to the capturing antibodies and thereby affixed indirectly to the nonmagnetic reaction chamber.