abstract |
Magnetic particles are used as the solid phase to carry out immunoassay. In a reaction vessel, the magnetic particles are mixed with a sample containing TSH as an analyte and a labeled antibody. A chemiluminescent label material is bound onto the magnetic particles with an immunoreaction. A fluid including the above mixture is introduced to a chamber inside a flow through cell, the chamber being sized to have a width greater than a depth. The magnetic particles in the fluid are trapped by a magnet so as to be spread in the planar form over a predetermined area within the chamber, while useless materials are discharged outwardly of the chamber. The chamber is then filled with a buffer solution containing an attractant. By applying a voltage to electrodes disposed in the chamber, the label material on the magnetic particles is excited to emit an electro-chemiluminescence. The luminescence is detected by a photomultiplier. |