Separation system and efficient capture of contaminants using magnetic nanoparticles

• US 7,699,979 B2
• Filed: 01/09/2006
• Issued: 04/20/2010
• Est. Priority Date: 01/07/2005
• Status: Expired due to Fees

• Current Assignee: The Board of Trustees of the University of Arkansas (University of Arkansas System)
• Original Assignee: The Board of Trustees of the University of Arkansas (University of Arkansas System)
• Inventors: Ye, Zunzhang, Varshney, Madhukar, Li, Yanbin
• Primary Examiner(s): Reifsnyder; David A
• Application Number:
  US11/328,808
• Publication Number:
  US 20070114181A1
• Time in Patent Office: 1,562 Days
• Field of Search: 210/138, 210/222, 210/695, 436/20, 436/56, 436/526, 435/173.1, 422/186.01, 366/273
• US Class Current: 210/138
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C02F 2209/36 Biological material, e.g. enzymes or ATP
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G01N 35/0098 involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C
• CPC Class Codes: Y10T 436/13 Tracers or tags

Abstract

Methods are disclosed for the capture, detection, separation, isolation and quantification of contaminants in a starting material. Also disclosed are competitive assay methods for the detection and quantification of contaminants in a starting material. Kits for use with the method are disclosed as well. A system for capturing, separating and/or concentrating contaminants from a material is also presented. The system captures, separates and/or concentrates contaminants such as bacteria, viruses, other microorganisms, and/or larger items, such as insects, from a variety of materials, such as food, and environmental and clinical materials. In general, the system uses a rotating magnetic field to mix the material with magnetic particles to capture the target contaminants, and a fixed magnetic field to separate and concentrate the captured target contaminants.

Claims

1. A system for separating a contaminant from a material that includes the contaminant, the system comprising:

a housing;

a chamber supported by the housing and configured to receive the material and a plurality of magnetic particles, the magnetic particles capable of binding an affinity moiety, wherein the affinity moiety is capable of binding to the contaminant;

a controller configured to produce a first signal to mix the magnetic particles with the material, such that at least a portion of the magnetic particles binds to the contaminant, and a second signal to separate the magnetic particles and the bound contaminant from the material; and

a magnetic field subsystem in communication with the controller and configured to create within the chamber a rotational magnetic field in response to the first signal and a fixed magnetic field in response to the second signal,

wherein the rotational magnetic field comprises a plurality of magnetic fields which rotate in opposite directions.

2. The system of claim 1, wherein the magnetic field subsystem comprises a plurality of pairs of electromagnetic coils disposed adjacent to the chamber, the pairs of coils being arranged in layers from a top to a bottom of the chamber.

3. The system of claim 1, wherein the magnetic particles comprise magnetic nanoparticles.

4. The system of claim 1, wherein the material is selected from the group consisting of a food product, an environmental sample and a clinical sample.

5. The system of claim 4, wherein the clinical sample is selected from the group consisting of a urine sample, a blood sample, a fecal sample, a swab from the surface of the skin, a swab from the surface of an organ, and a tissue sample.

6. The system of claim 4, wherein the food product is selected from the group consisting of a fruit, a vegetable, a raw food, a ready-to-eat food, a beef product, a pork product, a poultry product, a sea food product, or a dairy product.

7. The system of claim 6, wherein the poultry product is selected from the group consisting of a chicken carcass, a chicken carcass wash water sample, a deboned chicken, a ground poultry meat sample and a poultry patty.

8. The system of claim 4, wherein the environmental sample is selected from the group consisting of a water sample, an air sample and a soil sample.

9. The system of claim 1, wherein the contaminant is selected from the group consisting of a prokaryote, a eukaryote, a virus, a polypeptide, and a chemical.

10. The system of claim 9, wherein the chemical is selected from the group consisting of a herbicide and a pesticide.

11. The system of claim 10, wherein the herbicide is 2-chloro-4-(ethylamine)-6-(isopropylamine)-s-triazine.

12. The system of claim 9, wherein the polypeptide is selected from the group consisting of a toxin and a prion.

13. The system of claim 9, wherein the prokaryote is selected from the group consisting of Escherichia coli, Escherichia coli O157:

H7, Salmonella spp., and Listeria monocytogenes.

14. The system of claim 1, wherein the affinity moiety comprises an antibody.

15. The system of claim 1, wherein each magnetic particle is coupled to a linker capable of binding an antibody.

16. The system of claim 15, wherein the linker is selected from the group consisting of Protein A, Protein G, an Fc receptor, and an anti-Fc antibody.

17. The system of claim 16, wherein the linker comprises a bridging complex selected from the group consisting of:

biotin-streptavidin, biotin-avidin, Protein A-IgG, Protein G-IgG, and IgG-anti-IgG.