Devices, systems and methods for separating magnetic particles

• US 20100200405A1
• Filed: 02/05/2010
• Published: 08/12/2010
• Est. Priority Date: 02/09/2009
• Status: Active Grant

• Current Assignee: Caprotec Bioanalytics GmbH
• Original Assignee: Caprotec Bioanalytics GmbH
• Inventors: Lenz, Thomas
• Granted Patent: US 8,268,264 B2
• Time in Patent Office: Days
• US Class Current: 204/600
• CPC Class Codes: B03C 1/0332 using permanent magnets
• CPC Class Codes: B03C 1/288 disposed at the outer circumference of a recipient
• CPC Class Codes: B03C 2201/18 Magnetic separation whereby the particles are suspended in a liquid
• CPC Class Codes: B03C 2201/22 characterised by the magnetic field, e.g. its shape or generation
• 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 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

A method and device for separating from samples magnetic particles that contain capture compounds on their surfaces. The device includes a sheath including a magnet and including orienting pin adapted to concentrate or direct a magnetic field of the magnet; and a magnetizable plate with lid holes for receiving a vessel lid of a vessel, the magnetizable plate configured to receive the sheath and position the orienting pin over the vessel lid. In one method, magnetic beads with attached molecules are collected in the lids of the reaction vessel by the magnetic separator device provided herein and the separated magnetic particles, which carry the molecules of interest through affinity-based attachment chemistry and are held in the lid by the magnet of the device, are released into a new vessel containing a solution by removal of the separator device without the need for pipettes or liquid handling devices.

Claims

1. A device, comprising:

a sheath comprising a magnet and including a plurality of orienting pins that each concentrate or direct a magnetic field of the magnet; and

a magnetizable plate;

wherein;

the magnetizable plate is configured to receive the sheath and is configured to receive vessel lids;

the magnetizable plate is configured to position the orienting pins over the vessel lids;

each orienting pin is adapted to concentrate or direct a magnetic field of the magnet to a vessel lid in the magnetizable plate; and

when the vessel lids are engaged with the vessels, the magnetizable plate is positioned between the vessel lids and the vessels.

2. The device of claim 1, wherein:

the magnet is imbedded in the sheath;

the orienting pins are integrated into the sheath; and

each orienting pin concentrates or directs a magnetic field of the magnet to the middle of its associated vessel lid and allows for the concentrated collection of magnetic particles essentially or exactly in the middle of the lids.

3. The device of claim 1, wherein the magnet is a permanent magnet, a high performance magnet, a rare earth magnet or an electromagnet.

4. The device of claim 1, wherein the magnet is selected from among an R-cobalt magnet and an R—

Fe—

B magnet, wherein R is selected from among lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu)), scandium (Sc) and yttrium (Y).

5. The device of claim 1, wherein the magnet is a neodymium magnet.

6. The device of claim 1, wherein the magnet has a (BH)_max of from 5 MGOe to 50 MGOe, at least 25 MGOe, from 20 MGOe up to 90 MGOe;

or from 25 MGOe up to 50 MGOe.

7. The device of claim 1, wherein the magnet has a remanence from about 3 kG to about 20 kG.

8. The device of claim 1, wherein the magnet has an intrinsic coercivity of greater than 5 kOe.

9. The device of claim 1, wherein the sheath comprises a non-magnetic material.

10. The device of claim 1, wherein the sheath is aluminum or an aluminum alloy.

11. The device of claim 1, wherein the magnet is embedded in the sheath.

12. The device of claim 1, wherein the sheath includes a bottom comprising the orienting pins.

13. The device of claim 12, wherein the magnet is attached to one face of the bottom of the sheath.

14. The device of claim 13, wherein the magnet is attached to one face of the bottom of the sheath by magnetic attraction to the orienting pins, or by an adhesive, or by a mechanical connector.

15. The device of claim 1, wherein:

the magnet is attached to the bottom of the sheath; and

the sheath has no side walls;

or

the sheath has no front, rear or side walls and no top;

or

the sheath comprises at least two sides and the bottom and the at least two sides define a cavity sized to receive the magnet through an open top or an optional closed top that is removable to expose the cavity.

16. The device of claim 1, wherein:

the sheath comprises a bottom containing the orienting pins; and

the orienting pins traverse the thickness of the bottom of the sheath;

or

the orienting pins do not fully traverse the thickness of the bottom of the sheath leaving one face of the bottom of the sheath unpenetrated;

or

the orienting pins do not fully traverse the thickness of the bottom of the sheath leaving the face of the bottom of the sheath pointing towards the magnet unperforated;

or

the orienting pins do not fully traverse the thickness of the bottom of the sheath leaving the face of the bottom of the sheath pointing towards the lids of the vessels unperforated;

or

the orienting pins do not fully traverse the thickness of the bottom of the sheath and are embedded into the material of the bottom of the sheath leaving all faces of the bottom of the sheath unperforated.

17. The device of claim 1, wherein the orienting pins are of a material having a magnetic permeability higher than the magnetic permeability of the material from which the sheath is fabricated.

18. The device of claim 1, wherein the orienting pins are formed of iron, steel, a mu metal or a soft magnetic alloy comprising about 80% nickel, 5% copper, 2% chromium, and 15% iron (magnifer 75).

19. The device of claim 1, wherein:

one or more of the orienting pins is a magnet, and

the magnetic North pole face of the orienting pin(s) is positioned to face the magnetic South pole face of the magnet in the sheath or the magnetic South pole face of the orienting pin(s) is positioned to face the magnetic North pole face of the magnet in the sheath.

20. The device of claim 1, wherein the orienting pins in the sheath are arranged linearly or in a circular, rectangular or quadrangular array.

21. The device of claim 1, wherein the number of orienting pins in the sheath is an integer selected from among 2, 3, 6, 9, 12, 24, 36, 48 or 96 or a multiple thereof.

22. The device of claim 1, wherein:

the sheath further comprises a fit pin; and

the magnetizable plate further comprises a fit pin hole configured to receive the fit pin.

23. The device of claim 22, wherein:

the sheath includes an edge having one or more fit pins and an opposite edge having a different number of fit pins to ensure only one orientation for the magnetizable plate and the sheath;

or

the sheath includes one fit pin at one edge and two or more fit pins on the opposite edge, each pin configured to align with corresponding fit pin holes.

24. The device of claim 1, wherein the magnetizable plate is configured to accept a vessel lid of a vessel including multiple chambers.

25. A device of claim 1, wherein each of the sheath comprising the magnet and the magnetizable plate is rectangular or is circular.

26. The device of claim 1, wherein the magnetizable plate is formed of steel or iron or of a soft magnetic alloy comprising about 80% nickel, 5% copper, 2% chromium, and 15% iron (magnifer 75).

27. The device of claim 1, further comprising a rack for holding a plurality of vessels.

28. The device of claim 27, wherein:

the vessels comprise vials, and the rack is configured to receive the vials;

or

the vessels comprise a multi-well plate, and the rack is configured to receive the multi-well plate.

29. A method of separating magnetic particles from a sample in a vessel, comprising:

a) providing the device of claim 1;

b) placing one or more lids of the vessel(s) in the corresponding holes in the magnetizable plate of the separator device;

c) pressing the magnetizable plate with lids onto the vessel, engaging the lids with the vessel, thereby sealing the vessel;

d) rotating the separating device at an angle for a time sufficient for the magnetic particles to become attracted to and maintained in the lid;

e) returning the device to the starting position;

f) removing the device with attached magnetizable plate with attached lids containing the magnetic particles from the vessel;

g) replacing the vessel with a new vessel and engaging the lids containing the magnetic particles with the new vessel, thereby sealing the vessel; and

h) releasing the magnetic particles from the lid.

30. The method of claim 29, wherein:

if the magnet is a permanent magnet, the magnetic particles are released by disengaging the sheath comprising the magnet of the device from the magnetizable plate, thereby allowing the magnetic particles to be released from the lids into the new vessel;

or

if the magnet is an electromagnet, the magnetic particles are released by turning off the power to the electromagnet.

31. The method of claim 30, further comprising removing the magnetizable plate with lids.

32. The method of claim 31, further comprising discarding the old lids.

33. The method of claim 30, wherein the new vessel contains a wash solution.

34. The method of claim 29, wherein the magnetic particles comprise a biomolecule, a protein, a nucleic acid or a carbohydrate.

35. The method of claim 29, wherein the magnetic particles comprise a capture compound.

36. A method of isolating a target molecule from a sample, comprising:

incubating the sample with a capture compound comprising;

a sorting function comprising one member of a specific binding pair;

a reactivity function, wherein the reactivity function forms a covalent attachment to the target molecule upon irradiation with light; and

a variable selectivity function;

irradiating the reaction mixture with light, whereby a covalent bond is formed between the target molecule and the reactivity function;

adding magnetic particles that have on their surface the corresponding member of the specific binding pair of the sorting function; and

separating the magnetic particles from the reaction mixture using a device of claim 1.

37. The method of claim 36, wherein the light is UV light.

38. A kit, comprising:

a device of claim 1; and

magnetic particles and optionally vessels or multiwell plates and optionally instructions for use.

39. The kit of claim 38, further comprising a capture compound that comprises a sorting function.

40. The kit of claim 39, wherein the sorting function comprises one member of a specific binding pair.

41. The kit of claim 40, wherein the magnetic particles include on their surface the corresponding member of the binding pair.

42. The kit of any claim 39, wherein the sorting function is biotin and the magnetic particle includes on its surface avidin or streptavidin.

43. A system, comprising:

a device of claim 1;

a device for providing light;

a capture compound comprising a light-activated reactivity function; and

optionally a device for analysis of biomolecules.

44. The system of claim 43, wherein the device for analysis is selected from among a mass spectrometer, an electrophoretic separator device, a surface plasmon resonance device and a chromatography device.

45. The system of claim 44, wherein the mass spectrometer performs time of flight mass spectrometry with matrix-assisted laser desorption ionization (MALDI-TOF), quadrupole ion trap mass spectrometry, secondary ion mass spectrometry, accelerator mass spectrometry, inductively coupled plasma-mass spectrometry, Ion Mobility Spectrometry-MS, Surface Enhanced Laser Desorption Ionization (SELDI-TOF), tandem mass spectrometry or Electrospray Ionization (ESI) mass spectrometry.

46. The system of claim 43, further comprising a computer programmed for analysis of captured biomolecules.