Devices and Methods for Separating Magnetically Labeled Moieties in a Sample

• US 20130330739A1
• Filed: 04/05/2012
• Published: 12/12/2013
• Est. Priority Date: 04/27/2011
• Status: Active Grant

• Current Assignee: Becton, Dickinson & Co
• Original Assignee: Becton, Dickinson & Co
• Inventors: Yu, Liping
• Granted Patent: US 9,885,642 B2
• Time in Patent Office: Days
• US Class Current: 435/7.1
• CPC Class Codes: B03C 1/0332 using permanent magnets
• CPC Class Codes: B03C 1/035 Open gradient magnetic separators, i.e. separators in which the gap is unobstructed, characterised by the configuration of the gap
• CPC Class Codes: B03C 2201/18 Magnetic separation whereby the particles are suspended in a liquid
• CPC Class Codes: B03C 2201/26 for use in medical applications
• CPC Class Codes: G01N 1/34 Purifying; Cleaning processes or apparatus for extracting or separating nucleic acids from biological samples C12N15/1003
• 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

Abstract

Devices for separating magnetically labeled moieties in a sample are provided. Aspects of the devices include a magnetic field source, a first magnetic field guide having a wedge-shaped portion with an apex edge, and a second magnetic field guide having a wedge-shaped portion with an apex edge. The apex edge of the first magnetic field guide is aligned substantially across from and parallel to the apex edge of the second magnetic field guide, and the device is configured to separate magnetically labeled moieties from non-magnetically labeled moieties in the sample. Also provided are methods of using the devices, as well as systems and kits configured for use with the devices and methods.

Claims

1. A device for separating magnetically labeled moieties in a sample, the device comprising:

a magnetic field source;

a first magnetic field guide having a wedge-shaped portion with an apex edge; and

a second magnetic field guide having a wedge-shaped portion with an apex edge,

wherein one or more of the first and second magnetic field guides is configured to increase a magnetic flux from the magnetic field source, the apex edges of the first and second magnetic field guides are aligned substantially across from and parallel to each other, and the device is configured to separate magnetically labeled moieties from non-magnetically labeled moieties in the sample.

2. The device of claim 1, wherein the first and second magnetic field guides have cross-sectional profiles that taper to a point or are rounded at their apex edges.

3. The device of claim 1, wherein the apex edges of the first and second magnetic field guides each have a linear profile or a saw-tooth profile.

4. The device of claim 1, wherein the first and second magnetic field guides each comprise a soft magnet, and the magnetic field source comprises a permanent magnet.

5. The device of claim 1, further comprising a second magnetic field source, wherein the first magnetic field guide is disposed on a surface of the magnetic field source facing the second magnetic field guide and is configured to increase the magnetic flux from the magnetic field source, and the second magnetic field guide is disposed on a surface of the second magnetic field source facing the first magnetic field guide is configured to increase a magnetic flux from the second magnetic field source.

6. A method of separating magnetically labeled moieties in a sample, the method comprising:

(a) positioning in a magnetic separation device a conduit configured to direct a flow of a sample through the magnetic separation device, the magnetic separation device comprising;

(i) a magnetic field source;

(ii) a first magnetic field guide having a wedge-shaped portion with an apex edge; and

(iii) a second magnetic field guide having a wedge-shaped portion with an apex edge,

wherein one or more of the first and second magnetic field guides is configured to increase a magnetic flux from the magnetic field source, and the apex edge of the first magnetic field guide is proximal to and substantially parallel to the apex edge of the second magnetic field guide; and

(b) applying a magnetic field to separate magnetically labeled moieties from non-magnetically labeled moieties in the sample.

7. The method of claim 6, further comprising:

positioning the conduit away from the magnetic field; and

recovering the magnetically labeled moieties retained in the conduit.

8. The method of claim 7, wherein the positioning the conduit away from the magnetic field comprises one or more of removing the conduit from the device and moving the magnetic field source away from the conduit.

9. The method of claim 6, further comprising specifically attaching a magnetic label to target moieties in the sample prior to applying the magnetic field to the sample.

10. The method of claim 6, wherein the sample comprises a biological sample.

11. A system for separating magnetically labeled moieties in a sample, the system comprising:

(a) one or more magnetic separation devices for separating magnetically labeled moieties in the sample, wherein each of the one or more magnetic separation devices comprises;

(i) a magnetic field source;

(ii) a first magnetic field guide having a wedge-shaped portion with an apex edge; and

(iii) a second magnetic field guide having a wedge-shaped portion with an apex edge,

wherein one or more of the first and second magnetic field guides is configured to increase a magnetic flux from the magnetic field source, the apex edge of the first magnetic field guide is proximal to and substantially parallel to the apex edge of the second magnetic field guide, and the device is configured to separate magnetically labeled moieties from non-magnetically labeled moieties in the sample; and

(b) a conduit positioned in the magnetic separation device and configured to direct a flow of the sample through the magnetic separation device.

12. The system of claim 11, wherein the conduit is positioned such that a longitudinal axis of the conduit is substantially parallel to a longitudinal axis of the first magnetic field guide and a longitudinal axis of the second magnetic field guide.

13. The system of claim 11, wherein the conduit is substantially free from magnetic gradient enhancing materials.

14. The system of claim 11, wherein the system comprises a first magnetic separation device and a second magnetic separation device arranged downstream from the first magnetic separation device.

15. The system of claim 11, further comprising a flow cytometer arranged downstream from the one or more magnetic separation devices.