Patent ID: 6027944
Filing Date: 2000-02-22
Classification: G01N,Y10S

Abstract:
A capillary-fill biosensor device suitable for use in assaying a ligand in a liquid sample, said device comprising (1) a measurement zone, (2) least one spatially distinct calibration zone and (3) at least one spatially distinct auxiliary calibration zone wherein(1) the measurement zone comprises (a) a known amount of a releasable first ancillary specific binding reagent and (b) a measurement surface comprising an immobilized measurement specific binding reagent capable of specifically binding with at least one of the ligand, the first ancillary specific binding reagent, or a first binding partner which specifically binds to said ligand and said first ancillary specific binding reagent;wherein the first ancillary specific binding reagent is provided either on a surface of the measurement zone separate from the measurement surface or prebound to said immobilized measurement specific binding partner or reagent,(2) the calibration zone comprises (c) a known amount of at least one releasable second ancillary specific binding reagent and a calibration surface comprising an immobilized calibration specific binding reagent having binding sites identical in structure to those of the immobilized measurement specific binding reagent and capable of specifically binding with at least one of the ligand, the second ancillary specific binding partner and a second binding partner which specifically binds to said ligand and said second ancillary specific binding reagent, and(3) the auxiliary calibration zone comprises an auxiliary calibration surface comprising an immobilized first auxiliary calibration binding reagent or an immobilized first auxiliary calibration reagent capable of giving rise to a zero or non-zero signal without the need for the presence of an ancillary reagent;wherein the releasable reagents remain in their respective zones without mixing with each other in the assay following either sequential or simultaneous contact with the liquid sample to provide (a) a specific binding complex immobilized on the measurement surface which is correlative of the presence or amount of the ligand in the liquid sample, (b) a calibration specific binding complex immobilized on the calibration surface as a result of an identical specific binding reaction as occurs on the measurement surface so as to provide a measurement correlative of a known amount of said ligand, and, optionally, (c) a nonspecific binding complex immobilized on the auxiliary calibration zone to provide a measurement for correcting nonspecific background binding.