Patent ID: 9063132
Filing Date: 2015-06-23
Classification: B01L,G01N

Abstract:
1. A method comprising: depositing a first mixture comprising an antibody-linked enzyme and an antibody-magnetic particle conjugate in a dry state in a reagent control zone of a microfluidic device; introducing a liquid sample including an analyte to the reagent control zone in a channel portion of the microfluidic device through an inlet, wherein the analyte is capable of binding the antibody in the antibody-linked enzyme and the antibody in the antibody-magnetic particle conjugate; contacting the liquid sample containing the analyte with the first mixture to rehydrate the first mixture and form a second mixture, the second mixture including the analyte, the antibody-linked enzyme and the antibody-magnetic particle conjugate at the reagent control zone; causing the analyte to form an analyte complex with the antibody-linked enzyme and the antibody in the antibody-magnetic particle conjugate such that the complex may be moved under the influence of a magnetic field; rupturing a fluid reservoir containing a second liquid, the second liquid containing a substrate of the enzyme and introducing the second liquid through a first path to flow toward the reagent control zone; acquiring a sensor reading from the released second liquid which represents a baseline response as the second liquid passes over a measurement electrode on the way to the reagent control zone; forming an analyte complex: second liquid interface between the second liquid and the analyte complex at a junction in the reagent control zone; driving a portion of the second liquid along a second path to an overflow zone, wherein the second liquid encounters a set of electrodes having immobilized thereon a predetermined amount of enzyme, the enzyme being the same enzyme in the antibody-linked enzyme of the first mixture; reacting the second liquid with the immobilized enzyme to obtain a high control response; moving the analyte complex across the interface under the influence of a magnetic field; locating the complex over a measurement electrode; acquiring a measurement response in the form of an enzyme control signal due to conversion of substrate in the second liquid by the enzyme at a detection zone, the detection zone in proximity of the measurement electrode; modulating the measurement response according to signals acquired for baseline response and high control response values; and using the reagent enzyme control signal to validate or adjust the assay result.