DEVICES, SYSTEMS, AND METHODS FOR MAGNETIC SEPARATION

• US 20130017538A1
• Filed: 07/14/2011
• Published: 01/17/2013
• Est. Priority Date: 07/14/2011
• Status: Active Grant

• Current Assignee: Cell Microsystems, Inc.
• Original Assignee: Fluxion Biosciences Incorporated
• Inventors: Ionescu-Zanetti, Cristian, Nevill, Joshua Tanner, Conant, Carolyn G., Schwartz, Michael, Rudoff, Roger
• Granted Patent: US 10,240,186 B2
• Time in Patent Office: Days
• US Class Current: 435/6.11
• CPC Class Codes: B01L 2200/0652 Sorting or classification of particles or molecules
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/0883 Serpentine channels
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: B01L 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• 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 2201/26 for use in medical or biological applications
• CPC Class Codes: C12Q 1/6806 Preparing nucleic acids for analysis, e.g. for polymerase chain reaction [PCR] assay C12Q1/6804 takes precedence
• CPC Class Codes: C12Q 2563/143 Magnetism, e.g. magnetic label
• CPC Class Codes: C12Q 2565/629 being a microfluidic device
• CPC Class Codes: G01N 33/54326 Magnetic particles

Abstract

Methods, microfluidic devices, and instruments for magnetic separation of particles from a fluid are described. Examples include microfluidic devices having a removable portion. Examples include microfluidic devices having one or more regions of reduced fluid velocity. Examples further including instruments having pneumatic interfaces. Examples further includes instruments having controllable magnets, imaging components, or combinations thereof.

Claims

1. A method comprising:

providing a fluid containing a plurality of particles having magnetic labels in a microfluidic device, wherein the microfluidic device includes;

a first substrate at least partially defining a fluidic feature having an opening;

a second substrate reversibly coupled to the opening;

separating the plurality of particles having magnetic labels from the fluid at least in part by generating a magnetic field across the microfluidic device such that the plurality of particles having magnetic labels are driven toward the second substrate; and

removing the second substrate including the plurality of particles having magnetic labels from the opening.

2. The method of claim 1, wherein said separating the plurality of particles having magnetic labels from the fluid sample comprises positioning a magnet proximate the microfluidic device.

3. The method of claim 2, further comprising:

placing the microfluidic device into an analysis instrument including a magnet couple to a pneumatic interface; and

wherein said positioning a magnet proximate the microfluidic device comprises pneumatically deploying magnet through the pneumatic interface.

4. The method of claim 1, wherein said generating a magnetic field across the microfluidic device comprises generating a force on the plurality of particles having magnetic labels in a direction opposite to a gravitational force.

5. The method of claim 4, wherein said separating the plurality of particles having magnetic labels comprises sedimenting another plurality of particles substantially free from magnetic labels.

6. The method of claim 5, wherein said another plurality of particles include labels configured to increase the sedimentation velocity of the another plurality of particles.

7. The method of claim 1, further comprising generating an image of the particles having magnetic labels on the second substrate.

8. The method of claim 1, wherein the fluidic feature is a first fluidic feature, and wherein said introducing a fluid containing a plurality of particles having magnetic labels into a microfluidic device comprises introducing the fluid into a second fluidic feature of the microfluidic device, wherein the first and second fluidic features are in fluid communication, and wherein a cross-sectional dimension of the first fluidic feature is larger than a cross-section dimension of the second fluidic feature such that particles experience reduced flow velocity during flow in the first fluidic feature relative to the second fluidic feature.

9. The method of claim 1, wherein introducing a fluid sample containing a plurality of particles having magnetic labels into a microfluidic device comprises flowing the fluid sample into the fluidic feature in a first stream, wherein the method further comprises:

flowing another fluid into the fluidic feature in a second stream, and wherein the magnet is positioned such that the plurality of particles having magnetic labels in the first stream are transported across the second stream at least in part by the magnetic field.

10. The method of claim 1, further comprising analyzing the particles including magnetic labels, wherein said analyzing comprises cell biomarker analysis.

11. The method of claim 10, wherein said cell biomarker analysis includes genetic, RNA, protein-based, metabolic, or signaling biomarkers, or combinations thereof.

12. The method of claim 1, further comprising analyzing of one or more of the particles including magnetic labels using PCR, FISH, sequencing, RNA analysis, protein analysis, signaling analysis, phosphorylation state analysis, or combinations thereof.

13. The method of claim 1, wherein said particles comprise cells and wherein the method further comprises culturing the cells after separation.

14. A microfluidic device comprising:

a substrate at least in part defining;

an inlet port;

a first channel in fluid communication with the inlet port, wherein the first channel has first cross-sectional dimensions;

a fluidic feature in fluid communication with the first channel, wherein the fluidic feature has second cross-sectional dimensions, wherein at least one of the second cross-sectional dimensions is larger than the first cross-sectional dimensions; and

a frame coupled to a surface of the substrate, wherein the frame at least in part supports a well structure in fluid communication with the inlet port.

15. The microfluidic device of claim 14, wherein the well structure is coupled to a base, and wherein the base at least in part defines an opening configured to receive a magnet.

16. The microfluidic device of claim 14, wherein the substrate at least in part defines a second channel in fluid communication with the fluidic feature, and wherein the first and second channels are arranged such that a gravitational force is configured to transport particles from the first channel to the second channel during fluid flow through the fluidic feature.

17. The microfluidic device of claim 16, wherein the first channel is defined at a first depth in the substrate and the second channel is defined at a second depth in the substrate, wherein the first depth is different than the second depth.

18. The microfluidic device of claim 17, wherein the substrate further at least partially defines:

a third channel in fluid communication with the fluidic feature and defined at a third depth in the substrate wherein the third depth is different than the second depth.

a first outlet port in fluid communication with the second channel; and

a second outlet port in fluid communication with the third channel; and

wherein the frame further supports at least in part a second well structure in fluid communication with the first outlet port and a third well structure in fluid communication with the second outlet port.

19. The microfluidic device of claim 18, wherein the first and second channels are arranged such that another force is configured to transport particles including magnetic labels from the first channel to the third channel during fluid flow through the fluidic feature, and wherein the second well structure is configured to receive the particles including magnetic labels and the third well structure is configured to receive the particles transported at least in part using gravitational forces.

20. The microfluidic device of claim 14, wherein the substrate further at least in part defines an opening configured to receive a magnet to generate a magnetic field across the fluidic feature.

33. The microfluidic device of claim 14, wherein the at least one well of the well structure has a conically-shaped bottom portion.

34. The microfluidic device of claim 14, wherein the fluidic feature and the channel are sized to impart a lower fluid flow velocity to a particle within the fluidic feature than within the channel.

21-32. -32. (canceled)

35. An apparatus comprising:

a platform configured to receive a microfluidic device, wherein the microfluidic device includes;

a substrate at least in part defining;

an inlet port;

a first channel in fluid communication with the inlet port, wherein the first channel has first cross-sectional dimensions; and

a fluidic feature in fluid communication with the first channel, wherein the fluidic feature has second cross-sectional dimensions, wherein at least one of the second cross-sectional dimensions is larger than the first cross-sectional dimensions;

a well structure in fluid communication with the inlet port;

a cover configured to seal the well structure, wherein the cover includes a pneumatic interface to the well structure; and

a magnet positioned to generate a magnetic field across the fluidic feature.

36. The apparatus of claim 35, wherein the well structure is coupled to a base, and wherein the base at least in part defines an opening configured to receive the magnet.

37. The apparatus of claim 36, further comprising an actuator coupled to the magnet, wherein the actuator is configured to move the magnet from a rest position to a second position proximal the fluidic feature.

38. The apparatus of claim 36, wherein the cover is configured to rotate move from a first position to a second position coupled to the microfluidic device.

39. The apparatus of claim 38, wherein the apparatus includes a post coupled to the magnet, wherein the post is configured to position the magnet proximal the fluidic feature in the second position.

40. The apparatus of claim 36, further comprising a imager configured to image contents of the fluidic feature.

41. The apparatus of claim 36, wherein the imager is disposed on a first side of the substrate and the magnet is disposed on a second, opposite side of the substrate.

42. The apparatus of claim 36, wherein the apparatus is configured to perform cell biomarker analysis.

43. The apparatus of claim 42, wherein the cell biomarker analysis includes genetic, RNA, protein-based, metabolic, or signaling biomarker analysis, or combinations thereof.

44. The apparatus of claim 35, wherein the apparatus is configured to perform genetic analysis of a sample, including sequencing, polymorphism detection, hybridization, amplification, FISH analysis, expression analysis, or combinations thereof.