Method of loading a droplet actuator

• US 8,852,952 B2
• Filed: 05/04/2009
• Issued: 10/07/2014
• Est. Priority Date: 05/03/2008
• Status: Expired due to Fees

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Inventors: Pollack, Michael G., Thwar, Prasanna, Pamula, Vamsee K., Eckhardt, Allen, Shenderov, Alexander, Allen, Dwayne, Srinivasan, Vijay
• Primary Examiner(s): HIXSON, CHRISTOPHER
• Application Number:
  US12/990,815
• Publication Number:
  US 20110104816A1
• Time in Patent Office: 1,982 Days
• Field of Search: 422/500, 422/501, 422/502, 422/503, 422/504, 436/174, 436/180, 347/19, 204/403.01, 204/400, 204/452, 435/287.2, 435/287.1, 435/6.11, 435/288.7
• US Class Current: 436/180
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/022 Transponder chips
• CPC Class Codes: B01L 2300/023 Sending and receiving of information, e.g. using bluetooth
• CPC Class Codes: B01L 2300/024 Storing results with means integrated into the container
• CPC Class Codes: B01L 2300/0672 Integrated piercing tool
• 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 2400/0415 electrical forces, e.g. electrokinetic
• 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 2400/0478 pistons
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/049 vacuum
• CPC Class Codes: B01L 2400/0683 mechanically breaking a wall or membrane within a channel or chamber
• 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 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: G01N 2035/1046 : Levitated, suspended drops
• CPC Class Codes: G01N 27/44704 : Details; Accessories
• CPC Class Codes: G01N 35/0098 : involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C
• CPC Class Codes: Y10T 436/25 : including sample preparation
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The invention provides droplet actuators and droplet actuator cassettes including reagent storage capabilities, as well as methods of making and using the droplet actuators and cassettes. The invention also provides continuous flow channel elements and techniques for using electrodes to manipulate droplets in flowing streams. The invention also discloses methods of separating compounds on a droplet actuator. Various other aspects of the invention are also disclosed.

Claims

1. A method of loading a droplet actuator, the method comprising:

(a) providing a droplet actuator loading circuit comprising a primary fluid circuit arranged to flow fluid through a fluid path comprising a droplet operations gap of a droplet actuator and an external fluid circuit;

(b) filling the loading circuit, including the droplet operations gap, with a liquid filler fluid and thereby purging the loading circuit of air, whereby all liquid lines of the primary fluid circuit and the external fluid circuit are filled with the liquid filler fluid and are substantially free of air bubbles;

(c) flowing a reagent liquid into the external fluid circuit to form droplets in the liquid filler fluid contained therein using valves configured in the primary fluid circuit and/or the reagent fluid path to switch between;

(i) circulating liquid in the primary fluid circuit; and

(ii) flowing liquid from the one or more reservoirs comprising reagents and/or filler fluid into the primary fluid circuit; and

(d) flowing contents of the external fluid circuit into the droplet operations gap of the droplet actuator.

2. The method of claim 1 wherein filling the loading circuit, including the droplet operations gap, with a liquid filler fluid comprises flowing filler fluid into the primary fluid circuit via a filler fluid branch in the primary fluid circuit.

3. The method of claim 2 wherein the filler fluid branch in the primary fluid circuit is situated in the external fluid circuit.

4. The method of claim 1 wherein flowing reagent liquid into the external fluid circuit comprises flowing reagent into the primary fluid circuit via a reagent branch in the primary fluid circuit.

5. The method of claim 4 wherein the reagent branch in the primary fluid circuit is situated in the external fluid circuit.

6. The method of claim 4 further comprising loading different reagent droplets into the external fluid circuit.

7. The method of claim 6 wherein the different reagent droplets are selected by switching the reagent branch from one reservoir to another reservoir.

8. The method of claim 7 wherein the switching is effected by a robotic device configured to move a terminus of the reagent fluid path from one reservoir to another reservoir.

9. The method of claim 1 wherein the flowing of steps (c) and (d) is conducted using a single reversible pump.

13. The method of claim 1 wherein step (b) further comprises filling all channels of the droplet actuator with the liquid filler fluid, whereby all channels of the droplet actuator are substantially free of air bubbles.

10. A method of loading a droplet actuator, the method comprising:

(a) providing a droplet actuator loading circuit comprising a primary fluid circuit arranged to flow fluid through a fluid path comprising a droplet operations gap of a droplet actuator and an external fluid circuit;

(b) filling the loading circuit, including the droplet operations gap, with a liquid filler fluid and thereby purging the loading circuit of air, whereby all liquid lines of the primary fluid circuit and the external fluid circuit are filled with the liquid filler fluid and are substantially free of air bubbles;

(c) flowing a reagent liquid into the external fluid circuit to form droplets in the liquid filler fluid contained therein;

(d) flowing contents of the external fluid circuit into the droplet operations gap of the droplet actuator; and

(e) flowing liquid from the droplet operations gap through an overflow fluid path fluidly coupled into the droplet operations gap.

11. The method of claim 10 wherein flowing liquid from the droplet operations gap through an overflow fluid path comprises pumping the liquid through the overflow path into a reservoir.

12. The method of claim 11 wherein the reservoir and pump together comprise a syringe pump.

14. The method of claim 10 wherein filling the loading circuit, including the droplet operations gap, with a liquid filler fluid comprises flowing filler fluid into the primary fluid circuit via a filler fluid branch in the primary fluid circuit.

15. The method of claim 14 wherein the filler fluid branch in the primary fluid circuit is situated in the external fluid circuit.

16. The method of claim 10 wherein flowing reagent liquid into the external fluid circuit comprises flowing reagent into the primary fluid circuit via a reagent branch in the primary fluid circuit.

17. The method of claim 16 wherein the reagent branch in the primary fluid circuit is situated in the external fluid circuit.

18. The method of claim 16 further comprising loading different reagent droplets into the external fluid circuit.

19. The method of claim 18 wherein the different reagent droplets are selected by switching the reagent branch from one reservoir to another reservoir.

20. The method of claim 19 wherein the switching is effected by a robotic device configured to move a terminus of the reagent fluid path from one reservoir to another reservoir.

21. The method of claim 10 wherein the flowing of steps (c) and (d) is conducted using a single reversible pump.

22. The method of claim 10 wherein step (b) further comprises filling all channels of the droplet actuator with the liquid filler fluid, whereby all channels of the droplet actuator are substantially free of air bubbles.