Microfluidic systems including pipettor elements

• US 6,482,364 B2
• Filed: 05/03/2001
• Issued: 11/19/2002
• Est. Priority Date: 06/28/1996
• Status: Expired due to Term

• Current Assignee: Caliper Holdings Incorporated
• Original Assignee: Caliper Holdings Incorporated
• Inventors: Parce, J. Wallace, Knapp, Michael R.
• Primary Examiner(s): Soderquist, Arlen
• Application Number:
  US09/848,717
• Publication Number:
  US 20020017464A1
• Time in Patent Office: 565 Days
• Field of Search: 204/451, 204/453, 204/604, 422/65, 422/100, 436/47, 738/645.2, 738/646.1, 738/631.1, 738/631.2, 738/640.1, 738/641.1, 738/642.4, 738/642.5
• US Class Current: 422/503
• CPC Class Codes: B01F 33/3021 the components to be mixed being combined in a single independent droplet, e.g. these droplets being divided by a non-miscible fluid or consisting of independent droplets
• CPC Class Codes: B01F 33/30351 using hydrophilic/hydrophobic surfaces
• CPC Class Codes: B01F 33/30352 using roughness of the surfaces
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 2219/00891 Feeding or evacuation
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• CPC Class Codes: B01L 2400/0421 electrophoretic flow
• CPC Class Codes: B01L 3/021 Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• 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 3/502784 specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: G01N 27/44704 Details; Accessories
• CPC Class Codes: G01N 27/44743 Introducing samples
• CPC Class Codes: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027
• CPC Class Codes: H02N 11/006 Motors
• CPC Class Codes: Y10S 366/02 Micromixers: segmented laminar flow with boundary mixing orthogonal to the direction of fluid propagation with or without geometry influences from the pathway
• CPC Class Codes: Y10T 436/113332 : with conveyance of sample along a test line in a container or rack
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The present invention provides for techniques for transporting materials using electrokinetic forces through the channels of a microfluidic system. The subject materials are transported in regions of high ionic concentration, next to spacer material regions of high ionic concentration, which are separated by spacer material regions of low ionic concentration. Such arrangements allow the materials to remain localized for the transport transit time to avoid mixing of the materials. Using these techniques, an electropipettor which is compatible with the microfluidic system is created so that materials can be easily introduced into the microfluidic system. The present invention also compensates for electrophoretic bias as materials are transported through the channels of the microfluidic system by splitting a channel into portions with positive and negative surface charges and a third electrode between the two portions, or by diffusion of the electrophoresing materials after transport along a channel.

Claims

1. A system, comprising:

a microfluidic device that includes a body structure having at least first and second microscale channels disposed therein, and a pipettor element extending from the body structure that comprises a capillary channel disposed therethrough, the capillary channel being in fluid communication with at least one of the first and second microscale channels;

a first collection of sample sources positioned adjacent the body structure;

a translation system for bringing the pipettor element into contact with one or more sample sources in the first collection of sample sources; and

a material transport system operably coupled to the microfluidic device, for introducing sample material into the pipettor element from the sample sources.

2. The system of claim 1, wherein the pipettor comprises a capillary tube.

3. The system of claim 1, wherein the pipettor comprises an extended portion of the body structure.

4. The system of claim 1, wherein the first collection of sample sources comprises at least a first multiwell plate.

5. The system of claim 4, further comprising a plurality of multiwell plates positioned proximal to the microfluidic device.

6. The system of claim 5, further comprising a system for conveying each of the multiwell plates in the plurality of multiwell plates to a position adjacent the microfluidic device.

7. The system of claim 1, wherein the material transport system comprises a electrokinetic transport system operably coupled to the microfluidic device.

8. The system of claim 1, wherein the microfluidic device is positioned above the collection of sample sources, and the pipettor extends out of the body structure toward the collection of sample sources.

9. The system of claim 1 wherein said pipettor element comprises an electropipettor.

10. The system of claim 9 wherein the electropipettor extends from the body structure of the microfluidic device and comprises a capillary having a capillary channel disposed therethrough and at least one electrode operably coupled to the capillary, the capillary channel being fluidly connected to at least one of the at least two microscale channels, and wherein the electropipettor is oriented relative to the body structure to electrokinetically introduce materials into the capillary channel from one or more sample sources external to the body structure.

11. The system of claim 9 wherein the body structure of the microfluidic device comprises a planar structure, and the electropipettor extends orthogonally out of the planar body structure.

12. The system of claim 11 wherein the microfluidic device comprises:

a planar body structure having a first surface and a second surface on a side opposite from the first surface;

at least a first sample reservoir disposed in the first surface; and

wherein the electropipettor extends out of the second surface.

13. The microfluidic system of claim 1 wherein the translation system comprises means for moving at least one of said first collection of sample sources and said microfluidic device relative to one another.

14. The microfluidic system of claim 1 wherein the translation system comprises means for moving both of said first collection of sample sources and said microfluidic device relative to one another.