Recirculating fluidic network and methods for using the same

• US 20040180377A1
• Filed: 06/23/2003
• Published: 09/16/2004
• Est. Priority Date: 06/24/2002
• Status: Active Grant

• Current Assignee: Fluidigm Corporation
• Original Assignee: Fluidigm Corporation
• Inventors: Barco, Joseph W., Manger, Ian David, Nassef, Hany Ramez
• Granted Patent: US 8,168,139 B2
• Time in Patent Office: Days
• US Class Current: 435/7.1
• CPC Class Codes: B01L 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2300/088 Channel loops
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0655 pinch valves
• CPC Class Codes: B01L 3/5025 for parallel transport of multiple samples
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B81B 3/00 Devices comprising flexible or deformable elements, e.g. comprising elastic tongues or membranes B81B5/00 takes precedence
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: F04B 43/02 having plate-like flexible members, e.g. diaphragms F04B43/14 takes precedence
• CPC Class Codes: F04B 43/14 having plate-like flexible members
• CPC Class Codes: F16K 2099/0074 using photolithography, e.g. etching
• CPC Class Codes: F16K 2099/0078 using moulding or stamping
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 2099/0084 : Chemistry or biology, e.g. "lab-on-a-chip" technology
• CPC Class Codes: F16K 99/0001 : Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0003 : Constructional types of microvalves; Details of the cutting-off member
• CPC Class Codes: F16K 99/0026 : Valves using channel deformation
• CPC Class Codes: F16K 99/0036 : operated by temperature variations
• CPC Class Codes: F16K 99/0046 : using magnets
• CPC Class Codes: F16K 99/0051 : using electrostatic means
• CPC Class Codes: F16K 99/0059 : actuated by a pilot fluid
• CPC Class Codes: G01N 33/5304 : Reaction vessels, e.g. agglutination plates for solid-phase systems G01N33/543
• CPC Class Codes: G01N 33/54366 : Apparatus specially adapted for solid-phase testing
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The present invention provides a variety of microfluidic devices and methods for conducting assays and syntheses. The devices include a solid substrate layer having a surface that is capable of attaching ligand and or anti-ligand, and an elastomeric layer attached to said surface. Preferred embodiments have deflectable membrane valves and pumps, for example, rotary pumps associated therewith.

Claims

1. A microfluidic device adapted for conducting assays comprising a solid substrate layer having a surface that is capable of attaching ligand and/or anti-ligand, and an elastomeric layer attached to said solid substrate surface, wherein said elastomeric layer comprises:

(a) a plurality of first flow channels;

(b) a plurality of second flow channels each intersecting and crossing each of said first flow channels thereby providing a plurality of intersecting areas formed at intersections between said first flow channels and said second flow channels, wherein said plurality of first flow channels and said plurality of second flow channels are adapted to allow the flow of a solution therethrough, and wherein said solid substrate surface is in fluid communication with at least said intersecting areas of said plurality of first flow channels and said plurality of second flow channels, and wherein said plurality of first flow channels and/or said plurality of second flow channels are capable of forming a plurality of looped flow channels;

(c) a plurality of control channels;

(d) a plurality of first control valves each operatively disposed with respect to each of said first flow channel to regulate flow of the solution through said first flow channels, wherein each of said first control valves comprises a first control channel and an elastomeric segment that is deflectable into or retractable from said first flow channel upon which said first control valve operates in response to an actuation force applied to said first control channel, the elastomeric segment when positioned in said first flow channel restricting solution flow therethrough;

(e) a plurality of second control valves each operatively disposed with respect to each of said second flow channel to regulate flow of the solution through said second flow channels, wherein each of said second control valves comprises a second control channel and an elastomeric segment that is deflectable into or retractable from said second flow channel upon which said second control valve operates in response to an actuation force applied to said second control channel, the elastomeric segment when positioned in said second flow channel restricting solution flow therethrough;

(f) a plurality of loop forming control valves each operatively disposed with respect to each of said first and/or said second flow channels to form said plurality of looped flow channels, wherein each of said loop forming control valves comprises a loop forming control channel and an elastomeric segment that is deflectable into or retractable from said first and/or said second flow channels upon which said loop forming control valve operates in response to an actuation force applied to said loop forming control channel, the elastomeric segment when positioned in said first and/or said second flow channels restricting solution flow therethrough thereby forming said looped flow channel; and

(g) a plurality of recirculating pumps, and wherein each recirculating pump is operatively disposed with respect to one of said looped flow channels such that circulation of solution through each of said looped flow channels can be regulated by one of said recirculating pumps.

2. The microfluidic device of claim 1, wherein each of said plurality of recirculating pumps comprises more than one control channels each formed within said elastomeric layer and separated from said looped flow channel by an elastomeric segment which is deflectable into said looped flow channel in response to an actuation force.

3. The microfluidic device of claim 1, wherein actuation of both of said plurality of first control valves and said plurality of second control valves forms a plurality of holding valves each of which is operatively disposed with respect to each of said first and said second flow channels such that a holding space encapsulating each of said intersecting area is formed.

4. The microfluidic device of claim 1 further comprising a solution inlet for each of said first flow channels in fluid communication therewith for introduction of a first solution.

5. The microfluidic device of claim 4 further comprising a second solution inlet for each of said second flow channels in fluid communication therewith for introduction of a second solution.

6. The microfluidic device of claim 1, wherein said plurality of first flow channels and said plurality of second flow channels are located on the interface between said solid substrate layer and said elastomeric layer such that one side of each of said first and said second flow channels is formed by said solid substrate surface.

7. The microfluidic device of claim 1, wherein said plurality of first flow channels and said plurality of second flow channels are located within said elastomeric layer, and wherein each of said plurality of intersecting areas formed at intersections between said first flow channels and said second flow channels comprises a via which is in fluid communication with said solid substrate surface thereby forming a well that is adapted to collect a fluid therein.

8. The microfluidic device of claim 1 further comprising a plurality of first flow channel pumps, wherein each of said first flow channel pump is operatively disposed with respect to one of said first flow channels such that solution flow through each of said first flow channels can be regulated by one of the pumps.

9. The microfluidic device of claim 8 further comprising a plurality of second flow channel pumps, wherein each of said second flow channel pump is operatively disposed with respect to one of said second flow channels such that solution flow through each of said second flow channels can be regulated by one of the pumps.

10. The microfluidic device of claim 9, wherein each of said plurality of flow channel pumps comprises more than one control channels each formed within said elastomeric layer and separated from said flow channel by an elastomeric segment which is deflectable into said flow channel in response to an actuation force.

11. The microfluidic device of claim 1 further comprising a first solution outlet channel in fluid communication with each of said first flow channel such that the solution from each of said first flow channel flow out into said first solution outlet channel.

12. The microfluidic device of claim 1 further comprising a second solution outlet channel in fluid communication with each of said second flow channel such that the solution from each of said second flow channel flow out into said second solution outlet channel.

13. The microfluidic device of claim 1, wherein said solid support surface at each of said intersecting areas comprises a ligand that is capable of specifically binding to antiligand that are present in the solution.

14. A method of conducting a binding assay, comprising

(a) providing a microfluidic device comprising a solid substrate layer having a surface that is capable of attaching ligand and/or anti-ligand, and an elastomeric layer attached to said solid substrate surface, wherein said elastomeric layer comprises:

(i) a plurality of first flow channels;

(ii) a plurality of second flow channels each intersecting and crossing each of the first flow channels thereby providing a plurality of intersecting areas formed at intersections between the first flow channels and the second flow channels, wherein the plurality of first flow channels and the plurality of second flow channels are adapted to allow the flow of a solution therethrough, and wherein the solid substrate surface is in fluid communication with at least the intersecting areas of the plurality of first flow channels and the plurality of second flow channels, and wherein the plurality of first flow channels and/or the plurality of second flow channels are capable of forming a plurality of looped flow channels;

(iii) a plurality of control channels;

(iv) a plurality of first control valves each operatively disposed with respect to each of the first flow channel to regulate flow of the solution through the first flow channels, wherein each of the first control valves comprises a first control channel and an elastomeric segment that is deflectable into or retractable from the first flow channel upon which the first control valve operates in response to an actuation force applied to the first control channel, the elastomeric segment when positioned in the first flow channel restricting solution flow therethrough;

(v) a plurality of second control valves each operatively disposed with respect to each of the second flow channel to regulate flow of the solution through the second flow channels, wherein each of the second control valves comprises a second control channel and an elastomeric segment that is deflectable into or retractable from the second flow channel upon which the second control valve operates in response to an actuation force applied to the second control channel, the elastomeric segment when positioned in the second flow channel restricting solution flow therethrough;

(vi) a plurality of loop forming control valves each operatively disposed with respect to each of the first and/or the second flow channels to form the plurality of looped flow channels, wherein each of the loop forming control valves comprises a loop forming control channel and an elastomeric segment that is deflectable into or retractable from the first and/or the second flow channels upon which the loop forming control valve operates in response to an actuation force applied to the loop forming control channel, the elastomeric segment when positioned in the first and/or the second flow channels restricting solution flow therethrough thereby forming the looped flow channel; and

(vii) a plurality of recirculating pumps, and wherein each recirculating pump is operatively disposed with respect to one of the looped flow channels such that circulation of solution through each of the looped flow channels can be regulated by one of the recirculating pumps;

(b) applying an actuating force to the second control valves to restrict solution flow through each of the second flow channels;

(c) introducing a reagent comprising a ligand into at least one of the first flow channels under conditions sufficient to attach the ligand to the solid substrate surface;

(d) removing the actuation force to the second flow channel control channel and applying an actuation force to the first control channel such that solution flow through the first flow channel is restricted; and

(e) performing a binding assay by introducing a sample solution into the second flow channel under conditions sufficient to specifically bind an antiligand that may be present in the sample solution to the ligand that is covalently attached to the solid substrate surface.

15. The method of claim 14 further comprising removing any ligand that is not attached to the solid substrate surface from the first flow channel prior to introducing the sample solution into the second flow channel.

16. The method of claim 14, wherein said step (e) of performing binding assay comprises applying an actuating force to the plurality of loop forming control valves to form the plurality of looped sample flow channels;

and circulating the sample solution within each of the looped sample flow channels using the recirculating pump.

17. The method of claim 14, wherein said step (e) of performing binding assay comprises applying an actuating force to both of the plurality of first control valves and the plurality of second control valves after introducing the sample solution into the second flow channel such that a plurality of holding spaces is formed wherein each holding spaces encapsulates one of the intersecting areas thereby allowing a prolonged contact between the sample solution and the ligand that is attached to the solid substrate surface on the intersecting areas.

18. The method of claim 14, wherein the plurality of first flow channels and the plurality of second flow channels are located within the elastomeric layer, and wherein each of the intersecting areas formed at intersections between the first flow channels and the second flow channels comprises a via which is in fluid communication with the solid substrate surface thereby forming a well that is adapted to collect a fluid therein.

19. The method of claim 14, wherein the first flow channel is in communication with a pump, and wherein the reagent is transported through the first flow channel under the action of the pump.

20. The method of claim 19, wherein the pump comprises more than one control channels each formed within the elastomeric layer and separated from the first flow channel by an elastomeric segment that is deflectable into the first flow channel in response to an actuation force, whereby the reagent is transported along the first flow channel.

21. The method of claim 14, wherein the second flow channel is in communication with a pump, and wherein the sample solution is transported through the second flow channel under the action of the pump.

22. The method of claim 21, wherein the pump comprises more than one control channels each formed within the elastomeric layer and separated from the second flow channel by an elastomeric segment that is deflectable into the second flow channel in response to an actuation force, whereby the sample solution is transported along the second flow channel.

23. The method of claim 14, wherein said step (e) of performing binding assay comprises removing the elastomeric layer from the solid substrate surface and determining ligand/antiligand binding at each of the intersecting areas with a detector.

24. The method of claim 23, wherein the detector detects an optical signal within the intersecting areas.

25. The method of claim 24, wherein the detector detects a fluorescence emission, fluorescence polarization or fluorescence resonance energy transfer.

26. The method of claim 24, wherein the detector is an optical microscope, a confocal microscope or a laser scanning confocal microscope.

27. The method of claim 23, wherein the detector is a non-optical sensor selected from the group consisting of a radioactivity sensor, and an electrical potential difference sensor.

28. The method of claim 14, wherein the assay comprises detecting binding between a substrate and a cell receptor;

a substrate and an enzyme;

an antibody and an antigen;

a nucleic acid and a nucleic acid binding protein;

a protein and a protein;

a small molecule and a protein;

a small molecule and an oligonucleotide; and

a protein affinity tag and a metal ion.

29. The method of claim 14, wherein the assay is an assay for detecting a toxic effect on cells or a cell death assay, or a cell proliferation assay.

30. The method of claim 14, wherein the assay is an oligonucleotide binding assay or a peptide binding assay.

31. The method of claim 14, wherein the assay is an antimicrobial assay.

32. A method for producing a microfluidic device comprising:

(a) producing a control layer, a flow layer, and a via layer from an elastomeric polymer, wherein each of the control layer and the flow layer comprises grooves on its surface for forming control channels and flow channels, respectively;

(b) attaching the control layer to the flow layer such that the grooves in the control layer is attached to a top surface of the flow layer thereby forming a plurality of control channels and attaching the bottom surface of the flow layer to the via layer thereby forming a plurality of first flow channels and a plurality of second flow channels, wherein each first flow channels intersects and crosses each of the second flow channels thereby forming a plurality of channel intersections, and wherein each vias in the via layer is positioned at each channel intersections; and

(c) optionally attaching the elastomeric polymer produced in said step (b) to a solid substrate which is comprises a ligand bound to its surface or comprises a functional group which is capable of attaching a ligand.

33. The method of claim 32, wherein said step of producing the via layer further comprises etching the via layer to produce a plurality of vias.