Flow Paths Comprising One or Two Porous Beds

• US 20070241061A1
• Filed: 01/31/2005
• Published: 10/18/2007
• Est. Priority Date: 01/29/2004
• Status: Active Grant

• Current Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Original Assignee: Gyros Patent AB (Mesa Laboratories Inc.)
• Inventors: Thorsen, Gunnar, Inganas, Mats, Engstrom, Johan
• Granted Patent: US 8,133,438 B2
• Time in Patent Office: Days
• US Class Current: 210/749
• CPC Class Codes: B01L 2200/141 Preventing contamination, tampering
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/0681 Filter
• 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 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: G01N 30/461 with serial coupling of separation columns
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: Y10T 436/25125 Digestion or removing interfering materials

Abstract

A microfluidic device that comprises a microchannel structure in which there are one, two or more flow paths (101;201a,b;301a,a′,b) all of which comprises a porous bed I (104,204,304) that is common for all of the flow paths and exposes an immobilized reactant R that is capable of interacting with a solute S that passes through the bed. The characteristics are that at least one of the flow paths comprises/comprise a second porous bed II (105,205,305) that is placed upstream of porous bed I (104,204,304) and is dummy with respect to interaction with solute S but capable of interacting with a substance DS that is present in a liquid aliquot together with solute S and is capable of disturbing the result of the interaction between solute S and said immobilized reactant R. There is also disclosed a method utilizing the device and variant of the device in which the immobilized R is replaced with a generic affinity ligand L_I and/or porous bed II exposes a generic ligand L_II that may be different from L_I.

Claims

1. A microfluidic device comprising a microchannel structure in which there are one, two or more flow paths all of which comprises a porous bed I that is common for all of the flow paths, which bed exposes an immobilized reactant R that is capable of interacting with a solute S that passes through the bed, wherein at least one of the flow paths comprises a second porous bed II that is placed upstream of porous bed I and is dummy with respect to interaction with solute S but capable of interacting with a substance DS that is present in a liquid aliquot together with solute S and is capable of disturbing the result of the interaction between solute S and said immobilized reactant R.

2. The microfluidic device of claim 1, wherein porous bed I and porous bed II are physically separated from each other.

3. The microfluidic device of claim 1, wherein the upstream end of porous bed I is abutted to the downstream end of porous bed II.

4. The microfluidic device of claim 3, wherein there is a porous membrane between said upstream end and said downstream end.

5. The microfluidic device of claims 1-4, wherein at least one of porous bed I and porous bed II bed is a packed bed of particles and the remaining porous bed, if any, is a porous monolithic plug.

6. The microfluidic device of claim 1, wherein at least one of porous bed I and porous bed II comprises a solid phase material that is a size exclusion material.

7. The microfluidic device claim 1, wherein the disturbing substance is smaller than solute S and that at least porous bed II in at least one of said at least one flow path comprises a solid phase material that is a size exclusion material having an exclusion limit delaying the disturbing substance from passing through porous bed II) in relation to solutes.

8. The microfluidic device of claim 1, wherein at least one, two or more of the remaining ones of said one, two or more flow paths is/are devoid of porous bed II.

9. The microfluidic device of claim 1, wherein the porous bed II in said at least one, two or more flow paths comprises/comprise an immobilised reagent R_DS that is capable of interacting with the disturbing substance that is present together with a solutes.

10. The microfluidic device of claim 1, wherein said at least one flow path is two or more flow paths and that R_DS in at least one of said two or more flow paths differs from R_DS in at least one of the remaining ones of said two flow paths.

11. A microfluidic process carried out in a flow path of a microchannel structure of a microfluidic device and comprising transporting a liquid aliquot containing a solute S through a porous bed I that is placed in said flow path and exhibits an immobilized reactant R that is capable of interacting with solute S during the transport, characterized in comprising the steps of

(i) providing said flow path in a form that comprises a porous bed II that is upstream of porous bed I and dummy with respect to interaction with solute S but capable of interacting with a disturbing substance DS,

(ii) providing a liquid aliquot containing said solute S and said disturbing substance in said flow path in a position that is upstream of porous bed II,

(iii) transporting the aliquot through porous bed II, and

(iv) transporting subsequently solute S through porous bed I to allow for the interaction with reactant R.

12. A microfluidic device comprising a microchannel structure that comprises one, two or more flow paths each of which comprises a porous bed I that is common for all of said flow paths and at least one of which comprises a porous bed II which is upstream of porous bed I, wherein one or both of porous bed I and porous bed II in said at least one flow path comprises a solid phase material containing a generic ligand.

13. The microfluidic device of claim 12, wherein the generic ligand in porous bed II in one or more of said at least one flow path are the same as in porous bed I.

14. The microfluidic device of claim 12, wherein the generic ligand in porous bed II in one or more of said at least one flow path is an affinity counterpart (anti-ligand) to the ligand in porous bed I.

15. The microfluidic device of claim 12, wherein said ligand is biotin or anti-biotins.

16. The microfluidic device of claims 12, wherein there is only one flow path comprising both porous bed I and porous bed II.

17. The microfluidic device of claim 16, wherein the downstream end of porous bed II is abutted to the upstream end of porous bed I, possibly with a porous membrane between the ends.