Use of calcium in immunoassay for measurement of C-reactive protein
AssigneeEastman Kodak Company
InventorAnnie L. Wu
Life of this patent
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Abstract
A specific binding immunoassay method for reducing the "hook" effect for the measurement of C-Reactive Protein has been discovered for both solution and dry analytical elements comprising contacting a liquid sample containing C-reactive protein in the presence of calcium ions with (a) a first antibody Ab1 specific for C-reactive protein, Ab1 being immobilized on a water-insoluble substrate and (b) a labeled, unbound second antibody Ab2 specific for C-reactive protein to obtain a water-insoluble complex of Ab1, ligand, and Ab2; (2) separating the water-insoluble complex from the liquid sample and unreacted Ab2; and (3) measuring either the amount of Ab2 associated with said water-insoluble complex or the amount of unreacted Ab2 as an indication of the amount of C-reactive protein in the sample.
Claims8
A specific binding assay method comprising:
- (1) contacting a liquid sample containing C-reactive protein (CRP) in the presence of from 0.01M to 0.5M calcium ions with (a) a first polyclonal antibody Ab1 specific for CRP, Ab1 being immobilized on a water-insoluble substrate and (b) a labeled, unbound second monoclonal antibody Ab2 specific for CRP to obtain a water-insoluble complex of Ab1, ligand, and Ab2;
- (2) separating the water-insoluble complex from the liquid sample and unreacted Ab2;
- and
- (3) measuring either the amount of Ab2 associated with said water-insoluble complex or the amount of unreacted Ab2 as an indication of the amount of C-reactive protein in the sample.
An analytical element comprising a porous spreading zone and in the porous spreading zone, or a different zone, a first polyclonal antibody Ab1 specific to C-Reactive Protein (CRP), Ab1 being immobilized on a water-insoluble particulate substrate and a labeled, unbound second monoclonal antibody Ab2 specific for CRP, wherein calcium ions are incorporated into said porous spreading zone in an amount ranging from 0.01M to 0.5M.
Dependencies are inferred from the claim text.