Reagents for reducing leukocyte interference in immunoassays

• US 9,018,017 B2
• Filed: 04/15/2013
• Issued: 04/28/2015
• Est. Priority Date: 04/30/2010
• Status: Active Grant

• Current Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Point Of Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Campbell, John Lewis Emerson, Davis, Graham, Omakor, John Emegbero, Moss, Adam Roger, Guhados, Ganesh
• Primary Examiner(s): Gabel, Gail R
• Application Number:
  US13/862,632
• Publication Number:
  US 20130273576A1
• Time in Patent Office: 743 Days
• Field of Search: 435/7.1, 435/7.93, 435/7.94, 435/287.1, 435/287.2, 436/517, 436/518, 436/172, 436/175
• US Class Current: 436/175
• CPC Class Codes: G01N 2333/475 Assays involving growth factors
• CPC Class Codes: G01N 33/5306 Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding
• CPC Class Codes: G01N 33/5375 by changing the physical or chemical properties of the medium or immunochemicals, e.g. temperature, density, pH, partitioning
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/74 involving hormones or other non-cytokine intercellular protein regulatory factors such as growth factors, including receptors to hormones and growth factors
• CPC Class Codes: Y10T 436/25125 Digestion or removing interfering materials
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

Methods and devices for reducing interference from leukocytes in an analyte immunoassay are provided. In one embodiment, a method is provided comprising the steps of amending a biological sample such as a whole blood sample with one or more leukocidal reagents that reduce or eliminate the metabolic activity of leukocytes, and performing an immunoassay on the amended sample to determine the concentration of analyte in the sample. Preferably, the sample is amended with one or more enzymes and optionally one or more enzyme substrates and cofactors.

Claims

1. A method of performing an electrochemical immunoassay for a target analyte in a whole blood sample comprising:

contacting the whole blood sample with a leukocidal reagent, wherein said leukocidal reagent substantially inhibits phagocytic activity of leukocytes in the whole blood sample, and wherein the leukocidal reagent is a mitochondrial electron transport inhibitor or a mitochondrial membrane uncoupling agent; and

performing the electrochemical immunoassay on the leukocidal reagent-treated whole blood sample, at an immunosensor and detecting the target analyte.

2. The method of claim 1, wherein the leukocidal reagent is the mitochondrial electron transport inhibitor.

3. The method of claim 1, wherein the leukocidal reagent is the mitochondrial membrane uncoupling agent.

4. The method of claim 1, wherein the leukocidal reagent is the mitochondrial electron transport inhibitor or the mitochondrial membrane uncoupling agent and selected from the group consisting of cyanide, antimycin, rotenone, malonate, carbonyl cyanide p-[trifluoromethoxyl]-phenyl-hydrozone, 2,4-dinitrophenol, and oligomycin.

5. The method of claim 1, wherein the electrochemical immunoassay is a sandwich assay performed by contacting the leukocidal reagent-treated whole blood sample with the immunosensor comprising an immobilized first antibody to the target analyte, and a labeled second antibody to the target analyte.

6. The method of claim 1, wherein the electrochemical immunoassay is a competitive assay performed by contacting the leukocidal reagent-treated whole blood sample with the immunosensor comprising an immobilized first antibody to the target analyte, and a labeled target analyte.

7. The method of claim 1, wherein the leukocidal reagent-treated whole blood sample is contacted with beads opsonized for the leukocytes.

8. The method of claim 1, wherein the whole blood sample is amended with an anticoagulant.

9. The method of claim 1, wherein the target analyte is selected from the group consisting of Troponin I (TnI), Troponin T (TnT), Brain Natriuretic Peptide (BNP), N-terminal of the Prohormone Brain Natriuretic Peptide (NTproBNP), Prohormone Brain Natriuretic Peptide (proBNP), Human Chorionic Gonadotropin (HCG), Thyroid-Stimulating Hormone (TSH), Neutrophil Gelatinase Associated Lipocalin (NGAL), theophylline, digoxin, and phenytoin.