| abstract |
An instrument (A) detects in a sample the presence of an analyte. The sample includes electrically readable particles ( 126 ) with an agent attached thereto that binds with the analyte or is an analog of the analyte. The instrument includes a port for the sample and a pair of electrodes ( 25, 30 ), one of which has a surface portion ( 30 a ) with an agent thereat that binds with the analyte or is an analog of the analyte. The electrodes have a first position where they are separated a sufficient distance apart to enable the sample to move between the electrodes and a second position where the electrodes are in close proximity. A detection circuit, including the electrodes, has a first state when the analyte is absent and a second state when the analyte is present. A signaling device provides an indication of the state of the detection circuit. |