MULTI-COMPARTMENT DEVICE WITH MAGNETIC PARTICLES

• US 20100273142A1
• Filed: 12/16/2008
• Published: 10/28/2010
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Siemens Healthcare Nederland B.V. (Siemens AG)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Van Der Wijk, Thea, Bruyninckx, Michel J.M., Boamfa, Marius losif, Den Dulk, Remco, Prins, Menno Willem Jose, Koets, Maatje, Immink, Albert Hendrik Jan, Van Dam, Dirkjan Bernhard, Maas, Joost Hubert
• Granted Patent: US 10,092,903 B2
• Time in Patent Office: Days
• US Class Current: 435/4
• CPC Class Codes: B01L 2200/0647 Handling flowable solids, e.g. microscopic beads, cells, particles
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 2400/088 by specific surface properties
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001

Abstract

The present invention discloses microfluidic devices with a valve-like structure (3), through which magnetic particles can be transported with minimal transport of fluids. This allows sequential processing of the magnetic particles.

Claims

1. A method for transferring magnetic particles from a fluidic sample through a valve-like structure comprising the steps:

(a) providing a device comprising at least two compartments connected by a valve-like structure wherein the valve-like structure may allow the passage of said magnetic particles upon magnetic actuation and wherein the valve-like structure prevents the mixing of the two fluids in the absence of a magnetic force,

(b) filling a first of the at least two compartments with a fluidic sample comprising magnetic particles,

(c) applying a magnetic force that drags said magnetic particles across the valve-like structure transferring it from a first of the at least two compartments to a second compartment.

2. A method according to claim 1 wherein the valve-like structure is part of a capillary channel connecting the at least two compartments.

3. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein the valve-like structure comprises a visco-elastic medium, wherein the visco-elastic medium is selected from a gas, a fluid, a deformable solid or a combination thereof.

4. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein the valve-like structure comprises a hydrophobic barrier and the magnetic force drives the particles across the hydrophobic barrier.

5. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein the valve-like structure comprises a deformable obstruction and the magnetic force drives the particles through the deformable material.

5-1. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1 wherein the method additionally comprises two steps between step (b) and (c):

concentration of the magnetic particles close to the valve-like structure by magnetic actuation,

passing the particles by actuation with a magnetic force through the valve-like structure.

6. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein the first compartment is filled by the sample fluid comprising the magnetic particles and the second compartment is filled by another fluid.

7. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein a target attached to the magnetic particles is co-transported with the magnetic particles from the first compartment to the second compartment.

8. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein during the transport of particles from the first to the second compartment, the valve-like structure causes the particles to lose an essential part of the co-transported fluid of the first compartment before the particles enter the second compartment.

9. A method for transferring magnetic particles from a fluidic sample through a valve-like structure according to claim 1, wherein the ratio between the volume of the magnetic particles and the co-transported fluid of the first compartment is larger than 0.05.

10. A device for conducting a method according to claim 1 comprising at least two compartments connected by a valve-like structure wherein the valve-like structure prevents the mixing of the two fluids in the absence of a magnetic force.

11. A device for conducting a method according to claim 1 comprising at least two compartments connected by a valve-like structure and wherein the valve-like structure allows the passage of magnetic particles upon actuation by a magnetic force.

12. A device according to claim 10, wherein the valve-like structure comprises a visco-elastic medium, wherein the visco-elastic medium is selected from a gas, a fluid, a deformable solid or a combination thereof.

13. A device according to claim 10, wherein the valve-like structure comprises a hydrophobic barrier.

14. A device according to claim 13 wherein the valve-like structure comprises a capillary channel comprising at least two hydrophobic surfaces.

15. A device according to claim 10 wherein the compartments are in close proximity.

16. A device according to claim 10, wherein the valve-like structure comprises a deformable obstruction.

17. A system comprising a device according to claim 10 and further comprising a magnetic source selected from a group comprising an electromagnet, an integrated current wire, a permanent magnet and a mechanically moving permanent magnet or electromagnet.

18. Use of a device according to claim 10 in a biochemical assay selected from the group comprising binding/unbinding assay, sandwich assay, competition assay, displacement assay and enzymatic assay.

19. The use of a valve-like structure, which prevents the mixing of two fluids in the absence of a magnetic force and which allows the passage of magnetic particles upon actuation by a magnetic force in a microfluidic system or device.