Reducing leukocyte interference in non-competitive immunoassays
First Claim
1. A kit for performing a sandwich immunoassay for an analyte suspected of being present in a whole blood sample, comprising beads opsonized to leukocytes, a substrate immobilized first antibody to the analyte and a labeled second antibody to the analyte, wherein the opsonized beads are present in an amount in excess of the leukocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention is directed to methods and devices for reducing interference from leukocytes in an analyte immunoassay, and in particular in non-competitive immunoassays. In one embodiment, the invention is to a method comprising the steps of (a) amending a biological sample such as a whole blood sample with sacrificial beads; and (b) performing a non-competitive immunoassay on the amended sample to determine the concentration of said analyte in said sample. Preferably, the sample is amended with IgG-coated sacrificial beads.
-
Citations
46 Claims
- 1. A kit for performing a sandwich immunoassay for an analyte suspected of being present in a whole blood sample, comprising beads opsonized to leukocytes, a substrate immobilized first antibody to the analyte and a labeled second antibody to the analyte, wherein the opsonized beads are present in an amount in excess of the leukocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample.
-
17. A cartridge for performing a sandwich immunoassay for an analyte suspected of being present in a whole blood sample, the cartridge comprising:
-
(a) a sample inlet for receiving the blood sample; (b) a metering chamber for metering the blood sample to form a metered sample; (c) one or more dry reagent coating layers comprising beads opsonized to leukocytes and a labeled antibody to the analyte, wherein the opsonized beads are present in an amount in excess of the leukocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample; (d) an electrode comprising an immobilized antibody to the analyte; and (e) one or more pumping elements for moving a metered sample, fluidized beads, and the labeled antibody to the electrode. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A method of performing a sandwich immunoassay for an analyte suspected of being present in a whole blood sample comprising:
-
(a) exposing a whole blood sample suspected of containing the analyte to beads opsonized to leukocytes, and wherein the opsonized beads are present in an amount in excess of the leukocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample;
a substrate immobilized first antibody to the analyte; and
a labeled second antibody to form a complex comprising said first antibody, said analyte and said second antibody; and(b) detecting and measuring the amount of labeled ternary complex formed in step a) so as to determine the presence and amount of analyte in the whole blood sample. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
-
-
39. A method of substantially ameliorating white blood cell accumulation on an analyte immunosensor comprising antibody-coated assay beads to the analyte immobilized on an electrode, the method comprising the steps of:
-
(a) mixing a whole blood sample suspected of containing an analyte with beads opsonized to leukocytes to form an amended sample wherein white blood cells in the sample preferentially seek to phagocytose the beads opsonized to leukocytes, wherein the opsonized beads are present in an amount in excess of the leucocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample, and (b) contacting the amended sample with an immunosensor. - View Dependent Claims (40)
-
-
41. A method of performing an immunoassay for an analyte suspected of being present in a whole blood sample comprising:
-
(a) mixing a whole blood sample suspected of containing an analyte with an excess amount of beads opsonized to leukocytes sufficient to substantially sequester any leucocytes present in the sample to form an amended sample wherein white blood cells in the sample preferentially seek to phagocytose the opsonized beads; (b) contacting the amended sample with an immunosensor comprising antibody-coated assay beads to the analyte immobilized on an electrode forming a complex between said antibody-coated assay bead, said analyte and a second labeled antibody; (c) washing said blood sample from said immunosensor; and (d) detecting and measuring the amount of said labeled ternary complex formed in step b) onto said immunosensor and relating the amount of said labeled complex to the concentration of the analyte present in the whole blood sample.
-
-
42. A method of performing a sandwich immunoassay for an analyte suspected of being present in a whole blood sample, comprising:
-
(a) mixing a whole blood sample suspected of containing an analyte with an excess amount of opsonized beads to leucocytes sufficient to substantially sequester any leucocytes present in the sample to form an amended sample wherein white blood cells in the sample preferentially seek to phagocytose the opsonized beads; (b) contacting the amended sample with antibody-coated assay beads to the analyte under conditions effective to form a complex between said antibody-coated assay bead, said analyte and a second labeled antibody; (c) washing said blood sample from said antibody-coated assay beads; and (d) detecting and measuring the amount of said labeled ternary complex formed in step b) and relating the amount of said labeled complex to the concentration of the analyte present in the whole blood sample.
-
-
43. A test cartridge for performing an immunoassay for an analyte suspected of being present in a whole blood sample, the test cartridge comprising an immunosensor in a conduit, said immunosensor having an immobilized first antibody to the analyte, and said conduit having a dry reagent coating disposed therein, the dry reagent coating comprising beads opsonized to leukocytes, wherein the opsonized beads are present in an amount in excess of the leucocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample and a second labeled antibody to said analyte and being configured to dissolve into said blood sample.
- 44. A kit for performing a sandwich immunoassay for an analyte suspected of being present in a whole blood sample, comprising beads opsonized to leukocytes, a substrate immobilized first antibody to the analyte and a labeled second antibody to the analyte, wherein the opsonized beads are present in an amount sufficient to provide a dissolved bead concentration of at least 5 micrograms per microliter of sample which is an amount in excess of the leucocytes in the blood sample sufficient to substantially sequester any leucocytes present in the sample.
Specification