Reducing leukocyte interference in competitive immunoassays
First Claim
Patent Images
1. A kit for performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, comprising:
- beads opsonized to leukocytes,a labeled analyte, and a substrate immobilized antibody to the sample analyte and to the labeled 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 competitive analyte 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 opsonized for leukocytes; and (b) performing a 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.
35 Citations
58 Claims
-
1. A kit for performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, comprising:
-
beads opsonized to leukocytes, a labeled analyte, and a substrate immobilized antibody to the sample analyte and to the labeled 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A cartridge for performing a competitive immunoassay for a sample 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 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 sample analyte and to the labeled analyte; and (e) one or more pumping elements for moving the metered sample, dissolved opsonized beads, and the labeled analyte to the electrode. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A method of performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, comprising:
-
(a) exposing a whole blood sample suspected of containing the sample analyte to beads opsonized for leukocytes, a labeled analyte and a substrate immobilized antibody to the sample analyte and to the labeled 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; and (b) detecting and measuring the amount of labeled analyte complexed to said substrate immobilized antibody so as to determine the amount of sample analyte present in the whole blood sample. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
-
-
41. A method of performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, comprising:
-
(a) exposing a whole blood sample comprising leukocytes and suspected of containing the sample analyte to beads opsonized for the leukocytes under conditions effective for the leukocytes to preferentially phagocytose the opsonized beads 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; (b) contacting the blood sample with a substrate immobilized antibody in the presence of labeled analyte under conditions effective to form a first complex comprising said antibody and said sample analyte and a second complex comprising said antibody and said labeled analyte; and (c) determining sample analyte concentration based on the detected and measured amount of the second complex formed. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
-
-
53. A method of substantially ameliorating white blood cell accumulation on a competitive immunosensor comprising antibody-coated assay beads to a sample analyte immobilized on an electrode, the method comprising the steps of:
-
(a) mixing a whole blood sample suspected of containing the sample analyte with beads opsonized to leukocytes to form an amended sample wherein white blood cells in the sample preferentially seek to phagocytose the opsonized beads 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 in the presence of labeled analyte.
-
-
54. A method of performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, comprising:
-
(a) mixing a whole blood sample suspected of containing a sample analyte with an excess amount of beads opsonized to leukocytes sufficient to substantially sequester any leucocytes present in the sample and a labeled analyte 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 sample analyte immobilized on an electrode to form a first complex between the antibody-coated assay beads and the sample analyte and a second complex between the antibody-coated assay beads and the labeled analyte; (c) washing said blood sample from said immunosensor; and (d) detecting and measuring the amount of labeled analyte on said immunosensor and relating the amount of said labeled analyte to the concentration of the sample analyte present in the whole blood sample.
-
-
55. A test cartridge for performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, the test cartridge comprising an immunosensor in a conduit, said immunosensor having an immobilized antibody to the sample analyte, and said conduit having a dry reagent coating disposed therein, the dry reagent coating comprising beads opsonized to leucocytes, 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 labeled analyte and being configured to dissolve into said blood sample.
-
56. A kit for performing a competitive immunoassay for a sample analyte suspected of being present in a whole blood sample, comprising:
-
beads opsonized to leukocytes, a labeled analyte, and a substrate immobilized antibody to the sample analyte and to the labeled 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. - View Dependent Claims (57, 58)
-
Specification