Droplet-based washing

• US 20070241068A1
• Filed: 12/15/2006
• Published: 10/18/2007
• Est. Priority Date: 04/13/2006
• Status: Active Grant

• Current Assignee: Duke University, Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Duke University
• Inventors: Pamula, Vamsee K., Eckhardt, Allen E., Srinivasan, Vijay, Pollack, Michael G., Fair, Richard B.
• Granted Patent: US 8,613,889 B2
• Time in Patent Office: Days
• US Class Current: 210/806
• CPC Class Codes: B01F 31/65 the materials to be mixed being directly submitted to a pulsating movement, e.g. by means of an oscillating piston or air column
• 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 33/3031 using electro-hydrodynamic [EHD] or electro-kinetic [EKI] phenomena to mix or move the fluids
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• 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 2300/0864 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 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0421 electrophoretic flow
• CPC Class Codes: B01L 2400/0424 Dielectrophoretic forces
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 2400/043 magnetic forces
• CPC Class Codes: B01L 2400/0436 acoustic forces, e.g. surface acoustic waves [SAW]
• CPC Class Codes: B01L 2400/0442 thermal energy, e.g. vaporisation, bubble jet
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• 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 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: B01L 3/502792 : for moving individual droplets on a plate, e.g. by locally altering surface tension
• 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: B01L 7/525 : with physical movement of samples between temperature zones
• CPC Class Codes: Y10T 436/11 : Automated chemical analysis
• CPC Class Codes: Y10T 436/25 : including sample preparation
• CPC Class Codes: Y10T 436/25625 : Dilution
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The present invention relates to droplet-based washing. According to one embodiment, a method of providing a droplet in contact with a surface with a reduced concentration of a substance is provided, wherein the method includes: (a) providing a surface in contact with a droplet comprising a starting concentration and starting quantity of the substance and having a starting volume; (b) conducting one or more droplet operations to merge a wash droplet with the droplet provided in step (a) to yield a combined droplet; and (c) conducting one or more droplet operations to divide the combined droplet to yield a set of droplets comprising: (i) a droplet in contact with the surface having a decreased concentration of the substance relative to the starting concentration; and (ii) a droplet which is separated from the surface.

Claims

1. A method of providing a droplet in contact with a surface with a reduced concentration of a substance, the method comprising:

(a) providing a surface in contact with a droplet comprising a starting concentration and starting quantity of the substance and having a starting volume;

(b) conducting one or more droplet operations to merge a wash droplet with the droplet provided in step (a) to yield a combined droplet; and

(c) conducting one or more droplet operations to divide the combined droplet to yield a set of droplets comprising;

(i) a droplet in contact with the surface having a decreased concentration of the substance relative to the starting concentration; and

(ii) a droplet which is separated from the surface.

2. The method of claim 1 wherein step 1(c) yields a droplet in contact with the surface having a decreased quantity of the substance relative to the starting quantity.

3. The method of claim 1 wherein step 1(c) yields a droplet in contact with the surface having a substantially decreased quantity of the substance relative to the starting quantity.

4. The method of claim 1 wherein step 1(c) yields a droplet in contact with the surface having a substantially decreased concentration of the substance relative to the starting concentration.

5. The method of claim 1 wherein step 1(c) yields a droplet in contact with the surface having a volume which is approximately the same as the starting volume.

6. The method of claim 1 further comprising repeating steps 1(a)-1(c) until a predetermined concentration limit of the one or more components is met or exceeded in the droplet of 1(c)(i).

7. The method of claim 1 further comprising repeating steps 1(a)-1(c) until a predetermined maximum quantity of the one or more components is met or exceeded in the droplet of 1(c)(i).

8. The method of claim 1 further comprising repeating steps 1(a)-1(c) until a predetermined quantity and concentration of the one or more components is met or exceeded in the droplet of 1(c)(i).

9. The method of claim 6 wherein the predetermined concentration is a substantial reduction relative to the starting concentration.

10. The method of claim 6 wherein the predetermined concentration is a 99% reduction relative to the starting concentration.

11. The method of claim 6 wherein the predetermined concentration is a 99.9% reduction relative to the starting concentration.

12. The method of claim 6 wherein the predetermined concentration is a 99.99% reduction relative to the starting concentration.

13. The method of claim 6 wherein the predetermined concentration is a 99.999% reduction relative to the starting concentration.

14. The method of claim 7 wherein the predetermined quantity is a substantial reduction relative to the starting quantity.

15. The method of claim 7 wherein the predetermined quantity is a 99% reduction relative to the starting quantity.

16. The method of claim 7 wherein the predetermined quantity is a 99.9% reduction relative to the starting quantity.

17. The method of claim 7 wherein the predetermined quantity is a 99.99% reduction relative to the starting quantity.

18. The method of claim 7 wherein the predetermined quantity is a 99.999% reduction relative to the starting quantity.

19. The method of claim 1 wherein step 1(b) comprises merging two or more wash droplets with the droplet provided in step 1(a) to yield a combined droplet.

20. The method of claim 1 wherein the surface comprises a surface of one or more beads.

21. The method of claim 1 wherein the droplet provided in step 1(a) comprises a sample droplet.

22. The method of claim 1 wherein the droplet provided in step 1(a) comprises a reagent droplet.

23. The method of claim 1 wherein the droplet provided in 1(a) comprises a biological sample.

24. The method of claim 23 wherein the biological sample comprises a prepared and unprepared sample selected from the group consisting of whole blood, lymphatic fluids, serum, plasma, sweat, tear, saliva, sputum, cerebrospinal fluids, amniotic fluids, seminal fluids, vaginal excretions, serous fluids, synovial fluids, pericardial fluids, peritoneal fluids, pleural fluids, transudates, exudates, cystic fluids, bile, urine, gastric fluids, intestinal fluids, fecal samples, fluidized tissues, fluidized organisms, biological swabs and biological washes.

25. The method of claim 1 wherein the droplet provided in 1(a) comprises amplified nucleic acid.

26. The method of claim 1 wherein the wash droplet comprises a solution selected from the group consisting of water, deionized water, saline solutions, acidic solutions, basic solutions, detergent solutions and buffers.

27. The method of claim 1 wherein step 1(b) and/or 1(c) comprises one or more droplet operations selected from the group consisting of loading a droplet into the droplet microactuator;

dispensing one or more droplets from a source droplet;

splitting, separating or dividing a droplet into two or more droplets;

transporting a droplet from one location to another in any direction;

merging or combining two or more droplets into a single droplet;

diluting a droplet;

mixing a droplet;

agitating a droplet;

deforming a droplet;

retaining a droplet in position;

incubating a droplet;

heating a droplet;

vaporizing a droplet;

cooling a droplet;

disposing of a droplet;

transporting a droplet out of a droplet microactuator;

other droplet operations described herein; and

any combination of the foregoing.

28. The method of claim 27 wherein step 1(b) and/or 1(c) is electric field-mediated.

29. The method of claim 27 wherein step 1(b) and/or 1(c) is electrode-mediated.

30. The method of claim 27 wherein step 1(b) and/or 1(c) is electrowetting-mediated.

31. The method of claim 27 wherein step 1(b) and/or 1(c) is dielectrophoresis-mediated.

32. The method of claim 27 wherein step 1(b) and/or 1(c) is effected on a droplet microactuator.

33. The method of claim 32 wherein:

(a) the droplet microactuator comprises two substrates arranged relative to each other by a distance sufficient to define a space between the two substrates; and

(b) only one of the two substrates comprises electrodes for conducting droplet operations.

34. The method of claim 32 wherein:

(a) the droplet microactuator comprises two substrates arranged relative to each other by a distance sufficient to define a space between the two substrates; and

(b) both of the two substrates comprises electrodes for conducting droplet operations.

35. The method of claim 32 wherein:

(a) the droplet microactuator comprises two substrates arranged relative to each other by a distance sufficient to define a space between the two substrates;

(b) one of the two substrates comprises electrodes for conducting droplet operations; and

(c) the other of the two substrates comprises one or more reference electrodes.

36. The method of claim 32 wherein the droplet microactuator comprises a substrate comprising:

(a) electrodes for conducting droplet operations; and

(b) one or more reference electrodes.

37. The method of claim 27 wherein step 1(b) and/or 1(c) is effected on a droplet microactuator.

38. The method of claim 32 wherein:

(a) the droplet microactuator comprises two substrates arranged relative to each other by a distance sufficient to define a space between the two substrates;

(b) one or both of the two substrates comprises electrodes for sensing one or more droplet properties; and

(c) the method comprises sensing a property of the droplet.