Abstract: Automatic diagnostic apparatus includes: a controller for controlling operation of the apparatus and for processing data; a sensing system operably connected to the controller for performing an assay, preferably an electrochemical assay (more preferably an electrochemical immunoassay), of a sample and communicating data from the assay to the controller; voltage supply means for applying a potential differential to the sensing system; and output means for communicating processed data to a user.

Abstract: Automatic diagnostic apparatus comprises: a controller for controlling operation of the apparatus and for processing data; a sensing system operably connected to the controller for performing an assay, preferably an electrochemical assay (more preferably an electrochemical immunoassay), of a sample and communicating data from the assay to the controller; voltage supply means for applying a potential differential to the sensing system; and output means for communicating processed data to a user.

Abstract: An assay for the presence of an analyte or determining a biological or medical parameter comprising the steps of adding an assay component to a pH-sensitive material charged with magnetic particles, wherein the assay component causes a pH change which is a function of the analyte or parameter to be measured; subjecting the magnetic particles to an oscillating magnetic field; and measuring the effect of the magnetic field on the magnetic particles. The assay is an enzyme immunoassay. A kit for practicing the enzyme immunoassay is also described.