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DE-102009021201-B4 - Rod arrangement and method for extracting magnetizable particles from solutions

DE102009021201B4DE 102009021201 B4DE102009021201 B4DE 102009021201B4DE-102009021201-B4

Abstract

Rod arrangement (1) for extracting magnetizable particles (70) from solutions (60) in at least one cavity (50), the rod arrangement (1) comprising: - at least one guide element (90) which is fixed to a guide element traverse (100) and which is movable to a distal guide element position (90d) by means of the guide element traverse (100) which is driven by a guide element drive group (900) consisting of up to three independent and separately controllable drives (m9x, m9y, m9z), wherein the guide element traverse (100) is movable in the direction parallel to the guide element (90) and in at least one direction perpendicular to the guide element (90); - at least one rod element (20), wherein the rod element (20) is fixed to a rod element traverse (30), which is driven by a rod element drive group (200) with up to three drives (m2x, m2y, m2z) acting orthogonally to each other, and thus the rod element (20) is movable at least in one direction parallel to the at least one guide element (90) and in at least one direction perpendicular to the guide element (90) and is thereby insertable into and removed from the at least one guide element (90); - a magnetic element (110) which is arranged at a distal end section of the at least one rod element (20), wherein the magnetic element (110) is movable to a distal magnetic element position (110d) and wherein the distal magnetic element position (110d) is located at a distal end section of the at least one guide element (90); and - a covering (80) which closes the distal end section of the guide element (90).

Inventors

  • Ralf Griebel

Assignees

  • STRATEC SE

Dates

Publication Date
20260513
Application Date
20090513

Claims (20)

  1. Rod arrangement (1) for extracting magnetizable particles (70) from solutions (60) in at least one cavity (50), the rod arrangement (1) comprising: - at least one guide element (90) fixed to a guide element traverse (100), and movable to a distal guide element position (90d) by means of the guide element traverse (100), which is driven by a guide element drive group (900) consisting of up to three independent and separately controllable drives (m9x, m9y, m9z), wherein the guide element traverse (100) is movable in the direction parallel to the guide element (90) and in at least one direction perpendicular to the guide element (90); - at least one rod element (20), wherein the rod element (20) is fixed to a rod element traverse (30) which is driven by a rod element drive group (200) with up to three drives (m2x, m2y, m2z) acting orthogonally to each other, and thus the rod element (20) is movable at least in one direction parallel to the at least one guide element (90) and in at least one direction perpendicular to the guide element (90) and is thereby insertable into and removed from the at least one guide element (90); - a magnetic element (110) which is arranged on a distal end section of the at least one rod element (20), wherein the magnetic element (110) is movable to a distal magnetic element position (110d) and wherein the distal magnetic element position (110d) is located on a distal end section of the at least one guide element (90); and - a covering (80) which closes the distal end section of the guide element (90).
  2. Rod arrangement (1) according Claim 1 , wherein the magnetic element (110) can be moved through an opening (91) at the distal end of the guide element (90) into a distally exposed magnetic element position (110d*).
  3. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) is furthermore movable between a proximal guide element position (90p) and the distal guide element position (90d).
  4. Rod arrangement (1) according to one of the preceding claims, wherein the magnetic element (110) is further movable between a proximal magnetic element position (110p) and the distal magnetic element position (110d).
  5. Rod arrangement (1) according to one of the preceding claims, wherein the at least one rod element (20) is movable relative to the at least one guide element (90) between a proximal rod position (20p) and a distal rod position (20d).
  6. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) is movable independently of the magnetizable element (110).
  7. Rod arrangement (1) according to one of the preceding claims, wherein the at least one rod element (20) is movable independently of the at least one guide element (90).
  8. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) and the magnetic element (110) are jointly movable along the direction parallel to the at least one guide element (90).
  9. Rod arrangement (1) according to one of the preceding claims, wherein a mobility of the at least one guide element (90) comprises a mobility of the at least one guide element (90) with the magnetic element remaining in the distal magnetic element position (110d).
  10. Rod arrangement (1) according to one of the preceding claims, wherein the mobility of the at least one guide element (90) comprises mobility of the at least one guide element (90) with the magnetic element (110) remaining in the proximal magnetic element position (110p).
  11. Rod arrangement (1) according to one of the preceding claims, wherein the mobility of the at least one guide element (90) comprises mobility of the magnetic element (110) beyond a distal end of the at least one guide element (90), such that the magnetic element (110) is spaced apart from the at least one guide element (90) and the at least one guide element (90) does not follow the movement of the magnetic element (110).
  12. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) is fixed to a guide element mechanism for moving the at least one guide element (90).
  13. Rod arrangement (1) according Claim 12 , wherein the guide element mechanism comprises at least the guide element traverse (100).
  14. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) comprises non-magnetic materials.
  15. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) comprises a rod-like guide element.
  16. Rod arrangement (1) according to one of the preceding claims, wherein the at least one guide element (90) comprises a cylindrical tube.
  17. Rod arrangement (1) according Claim 16 , wherein the cylindrical tube comprises a thin-walled cylindrical tube.
  18. Rod arrangement (1) according to one of the preceding claims, further comprising a rod element mechanism in which the at least one rod element (20) is fixed for movement of the at least one rod element (20), wherein the rod element mechanism comprises at least the rod element traverse (30).
  19. Rod arrangement (1) according to one of the preceding claims, wherein the at least one rod element (20) comprises non-magnetic materials.
  20. Rod arrangement (1) according to one of the preceding claims, wherein the at least one rod element (20) comprises a cylindrical tube.

Description

Field of invention The invention relates to rod arrangements for extracting magnetizable particles from solutions in at least one cavity. Furthermore, the invention relates to methods for extracting magnetizable particles from a solution in at least one cavity. Finally, the invention relates to magnetic elements for extracting magnetizable particles. Background of the invention Rod arrangements are known in the art for the extraction of biomolecules using magnetizable particles. The magnetizable particles are initially contained in a solution within a cavity. Under suitable conditions, the biomolecules bind to these magnetizable particles. Suitable conditions include the addition of a binding buffer and possibly lysis of the biomolecules, as is known in the art. The magnetizable particles are bound to the biomolecules. A magnetic element in the rod assembly attracts the magnetizable particles and, consequently, the bound biomolecules. Multiple purification steps are typically used to extract the magnetizable particles. The purity of the magnetizable particles on the rod assembly increases with each purification step. The magnetizable particles, along with the bound biomolecules, are typically moved from one cavity to the next using the rod assembly. Simple magnetizable rod assemblies are known in the prior art. These rod assemblies are used, for example, in laboratory automation devices to transport magnetizable particles. In the prior art, a rod is often encased in a shell that is closed at the bottom but open at the top. The rod is then placed in a solution containing magnetizable particles. A magnetic element inside the rod is moved to a region near the lower end, i.e., the distal end of the rod. The magnetic attraction enables the magnetizable particles to be transported from the solution into further cavities. To release the magnetizable particles into the further cavity, the magnetic element is switched off. Switching off the magnetic element can be achieved by removing it from the shell. Alternatively, switching off the current flow through the magnetic element is possible, provided the magnetic element is implemented as an electromagnet. WO 198705536 Carbomatrix (1986) describes a method for manipulating magnetizable particles using magnetic elements. A plastic sheath surrounds the magnetizable rod. This sheath is essentially non-magnetic and typically consists of a thin-walled, non-magnetizable, and non-remanent material. The Carbomatrix system further describes a mobility of the magnetic element within the non-magnetic sheath. A distal end of the plastic sheath features a stepped profile. This stepped profile ensures that the magnetizable particles adhere primarily to the tip and not to the side of the plastic sheath. US 20060266130 (Festo, 2005) describes an automated processing device with magnetizable rods and magnetizable particles. Furthermore, this patent application provides a comprehensive overview of the development of so-called "magnetic beads" technologies. In first-generation magnetic beads, magnets were attached from below to attract the magnetizable particles downwards. This was followed by various arrangements with magnetizable rods that could be inserted into cavities from above. The Festo system from 2005 is designed for relatively large magnetizable particles that achieve high velocities within a solution. The Festo system from 2005 also provides only a small magnetically effective area. A magnetically effective area is defined as a surface of the enclosure that is permeated with a sufficiently strong and inhomogeneous magnetic field to attract magnetizable particles. The magnetically effective area is determined by the extent of a region sufficiently permeated by an inhomogeneous magnetic field and essentially by the intersection of this sufficiently inhomogeneous magnetic field-permeated region with the casing or the walls of the cavities. The Festo system from 2005 is not suitable for use with small magnetizable particles. The magnetizable particles known in the prior art have a diameter in the range of a few micrometers to a few tens of micrometers. In the following, small magnetizable particles will be understood to mean magnetizable particles with a diameter of less than one micrometer, for example, in the range of 100 to 500 nm. These magnetizable particles with a diameter of less than one micrometer are also referred to as "nanobeads". WO 8606493 Labsystems (1986) describes a method for performing immunoassays using magnetizable particles and magnetizable rods. The Labsystems system from 1986 also allows for radiation measurement of the magnetizable particles that adhere to the magnetizable rod. The magnetizable rod has a magnetic element at its tip. This magnetic element is a short bar magnet, meaning its length is comparable to or less than the diameter of the bar magnet. In the Labsystems system from 1986, the magnetically effective area for extracting magnetizable par