Device and method for treating magnetic particles

• US 20050013741A1
• Filed: 11/07/2002
• Published: 01/20/2005
• Est. Priority Date: 11/19/2001
• Status: Active Grant

• Current Assignee: Abbott Molecular Incorporated (Abbott Laboratories)
• Original Assignee: chemagen Biopolymer-Technologie AG (Revvity, Inc.)
• Inventors: a' Brassard, Lothar
• Granted Patent: US 7,384,559 B2
• Time in Patent Office: Days
• US Class Current: 422/99
• CPC Class Codes: B03C 1/288 disposed at the outer circumference of a recipient
• CPC Class Codes: B03C 2201/26 for use in medical or biological applications
• 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

Abstract

The present invention relates to magnetic separators for separating magnetic particles from volumes of 1-500 ml for laboratory uses, especially in the field of molecular biology, wherein movable permanent magnets and/or movable reaction receptacles are used. Thus, magnetic particles can for example be collected on the wall of a reaction vessel and then be collected at the bottom of the reaction vessel by moving the magnets in a downward direction.

Claims

1. A device for treating magnetizable or magnetically attractable particles which are present in a liquid, comprising:

a holder for holding at least one reaction vessel with the liquid containing the particles;

at least two movably arranged permanent magnets;

a drive unit for moving the permanent magnets;

said permanent magnets being arranged in pairs and opposite to each other, and being movable in a vertical direction relative to the level of the liquid held in said holder;

the distance between the two permanent magnets of a pair being dimensioned or adjustable such that a reaction vessel of said at least one reaction vessel can be positioned therebetween;

the movement of the permanent magnets taking place so that each permanent magnet of said paired arrangement being alternately brought from a first position or start position, in which said permanent magnet is at a distance from one vessel of said at least one reaction vessel and said permanent magnet having essentially no influence on said particles, to a second or other position (work position), in which said permanent magnet is located laterally next to said one reaction vessel eenieefed and exerts a magnetic force on the particles, and with said two permanent magnets of said paired arrangement alternating with each other in taking over the above-mentioned first position or the above-mentioned second position, relative to the reaction vessel positioned between the magnets, and alternating between the said positions at a predetermined velocity and/or for a predetermined duration.

2. A device according to claim 1, wherein the drive unit of the movable permanent magnets is programme-controlled by a device selected from the group consisting of an integrated microprocessor control unit and a computer connected via an interface.

3. A device according to claim 1 wherein at least one of

the velocity,

the frequency,

the number of cycles of the movements of the magnets,

the duration of the pause intervals between the movements,

the position of said first or other working position in vertical direction, and

the sequence in which the permanent magnets take up said positions is predeterminable or controllable by a programme.

4. A device according to claim 1 wherein the two permanent magnets of said paired arrangement are mechanically coupled to each other so that, relative to the reaction vessel, one magnet is located in said first position when the other magnet is located in the said second or other position, and vice versa.

5. A device according to claim 1 wherein the two permanent magnets of said paired arrangement are coupled to each other so that the vertical directions of movement of each magnet of said paired arrangement are opposite to each other.

6. A device according to claim 1 wherein the drive unit of the permanent magnets comprises at least one of electro-motors and a pneumatic, hydraulic or electromagnetic drive means.

7. A device according to claim 1 and further comprising a plurality of said pair-wise arranged permanent magnets arranged in a row.

8. A device according to claim 1 and further comprising an elution position in which one permanent magnet is located at the bottom end of and beside the reaction vessel, and in which said permanent magnet exerts a magnetic force on the particles.

9. A device according to claim 1 wherein said holder is arranged to enable movement in a vertical direction, and can be brought from a lower or starting position to a predeterminable upper position by a drive means, so that said permanent magnet, when located in said working position at said reaction vessel, is positioned at the bottom end of the reaction vessel and is located at said elution position.

10. A device according to claim 1 wherein said drive unit is movably arranged and can be brought from an upper or starting position to a predeterminable lower position by a drive means, so that said permanent magnet, when located in said working position at said reaction vessel, is positioned at the bottom end of the respective reaction vessel, and wherein at least one of the direction, distance, velocity of the movement of the drive unit, or intermediate pause intervals are predeterminable or programmable.

11. A device according to claim 1 wherein said holder is arranged so as to be movable in at least one of a horizontal direction or a vertical direction, and wherein at least one of the direction, distance, velocity of the movement, or the intermediate pause intervals are predeterminable or programmable.

12. A device according to claim 1 and further comprising at least one device selected from the group consisting of at least one device for the sucking-off of liquid from said at least one reaction vessel and at least one pipetting device for dosing defined volumes of liquid to said at least one reaction vessel, each of these operational steps being programme-controllable.

13. A process for treating magnetizable or magnetically attractable particles, which are present in a reaction vessel, in order to resuspend the particles in a liquid to be added thereto, comprising the steps of:

positioning a permanent magnet from a pair of permanent magents in alternating order at opposite sides of the reaction vessel, so that said permanent magnet is located beside the reaction vessel concerned and exerts a magnetic force on the particles.

14. A process for treating magnetizable or magnetically attractable particles, which are present in a reaction vessel, with a liquid, said process comprising the steps of:

adding a predetermined amount of a liquid to a pellet containing magnetic particles;

resuspending the pelletized particles and mixing with the liquid, wherein the resuspending and mixing step further comprises the steps of

positioning said reaction vessel between two permanent magnets which are arranged in a pair and opposite to each other, said permanent magnets being vertically movable, and

alternatively moving said permanent magnets vertically so that each permanent magnet of a paired arrangement is brought from a first position or starting position, wherein said magnet is located at a distance from a reaction vessel and wherein said magnet has no influence on said particles, to a second or to another position (working position), wherein said magnet is located laterally next to the reaction vessel and wherein said magnet exerts a magnetic force on the particles, with the two permanent magnets of said paired arrangement alternating with each other in taking over said first position and said working position relative to the reaction vessel arranged between the magnets, and changing between the said positions at a predeterminable velocity and for predeterminable durations.

15. A process according to claim 14, and further comprising a binding, washing or elution step which uses a liquid selected from the group consisting of a binding liquid, a wash liquid and an elution liquid.

16. A process according to claim 14 wherein the resuspending and mixing step is carried out in such a manner that

said reaction vessel is positioned between two vertically movable permanent magnets which are arranged in a pair and opposite to each other, and

that each permanent magnet of said paired arrangement is alternately brought into an elution position, in which said magnet is located laterally next to and at the bottom end of the reaction vessel, and in which said magent exerts a magnetic force on the particles.

17. A process according to claim 16, wherein said permanent magnet is brought to said elution position by

moving the reaction vessel or reaction vessel holder carrying the reaction vessel in vertical direction (c) from a lower or starting position to a predeterminable upper position, relative to the working position of the permanent magnet;

and

moving said starting position of said pair of permanent magnets to a predeterminable lower position, so that said permanent magnet, when located in said work position at said reaction vessel, is positioned at the bottom end of the reaction vessel.

18. A process according to claim 14 wherein said movements of the permanent magnets, or respectively of the reaction vessel holder, are carried out automatically.

19. A process according to claim 14 wherein the resuspension step further comprises a dwell time of a predetermined length following each altering of the position of the permanent magnets.

22. A process according to claim 14 wherein said movements of the permanent magnets, or of the reaction vessel holder, are programme-controlled.

20. (cancelled)

21. (cancelled)