US 5,296,347 A · Bridge immunoassay

Abstract

Disclosed is a novel immunoassay methodology, bridge immunoassay, which employs a primary free solution analyte/receptor binding reaction, for example, in a sandwich-type format (two or more analyte receptors), in a competitive format (single analyte receptor) or in a related immunoassay format, and a universal solid phase and capture system. The universal capture system comprises a first receptor bound to a solid phase and a bridge receptor (a second receptor) which functions both as a ligand for said bound first receptor and as a receptor for a ligand conjugated to a sample analyte receptor (a third receptor). The bridge receptor is used to immobilize the immunocomplexes formed free in solution by linking them to the bound first receptor. The universal capture system can be used for assays for any analyte as the bridge receptor binds to a ligand, for example, a hapten or binding protein, conjugated to the sample analyte receptor. Methods, compositions and test kits for such bridge immunoassays are provided.

Claims41

Dependent claims

A method of immunoassay for an analyte in a liquid sample which comprises preparing or obtaining a solid phase to which is bound a first receptor which is selected from the group consisting of avidin and streptavidin and has as its ligand biotin conjugated to a second receptor which is an anti-hapten antibody;

wherein the second receptor is a bridge receptor which has as its ligand a hapten conjugated to a third receptor;
wherein the third receptor is an antibody that is not connected to a soluble liquid matrix and has as its ligand the analyte under assay;
contacting the liquid sample containing said analyte with said third receptor in either the presence or absence of said solid phase;
linking the third receptor to the solid phase by contacting the third receptor with the bridge receptor either in the presence or in the absence of the solid phase wherein the solid phase can be introduced to the liquid sample before, after or simultaneously with the bridge receptor;
and
detecting and/or quantitating the analyte under assay;
wherein the molar ratio of the second receptor to the third receptor is greater than 1:1.

4 more elements

A method of immunoassay for an analyte in a liquid sample comprising the steps of:

(a) incubating, in the presence of a solid phase to which a first receptor is bound wherein the first receptor is selected from the group consisting of avidin and streptavidin, a mixture comprising the liquid sample containing the analyte and two receptors to the analyte, one of which is labeled and one of which is conjugated to a hapten, wherein the receptor which is conjugated to a hapten is not connected to a soluble liquid matrix, for a sufficient time for sandwich immunocomplexes to form wherein said receptors are antibodies;
(b) adding to said mixture a bridge receptor which is an anti-hapten antibody which has as its ligand the hapten conjugated to said analyte receptor and to which biotin is conjugated as the ligand for the first receptor;
(c) incubating the mixture formed in step (b) for sufficient time for the immunocomplexes formed in step (a) to be immobilized upon the solid phase;
and
(d) determining the amount of label that has been immobilized upon the solid phase or remains in the liquid sample and, therefrom the amount of analyte that had been present in the sample;
wherein the molar ratio of the second receptor to the third receptor is greater than 1:1.

3 more elements

Dependencies are inferred from the claim text.

Bridge immunoassay

Life of this patent

Bridge immunoassay

Life of this patent

Abstract

Claims41