Device for generating droplets

• US 10,272,432 B2
• Filed: 10/15/2018
• Issued: 04/30/2019
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: Bio-Rad Laboratories Incorporated
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Ness, Kevin D., Kelly, Christopher F., Masquelier, Donald A.
• Primary Examiner(s): White, Dennis
• Application Number:
  US16/160,783
• Publication Number:
  US 20190046987A1
• Time in Patent Office: 197 Days
• CPC Class Codes: B01F 23/41 Emulsifying
• CPC Class Codes: B01F 33/3011 using a sheathing stream of a fluid surrounding a central stream of a different fluid, e.g. for reducing the cross-section of the central stream or to produce droplets from the central stream
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/0689 Sealing
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0829 Multi-well plates; Microtitration plates
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/0275 Interchangeable or disposable dispensing tips
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/502723 characterised by venting arrangements
• 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: C12Q 1/6806 Preparing nucleic acids for analysis, e.g. for polymerase chain reaction [PCR] assay C12Q1/6804 takes precedence
• CPC Class Codes: G01N 2035/00148 Test cards, e.g. Biomerieux or McDonnel multiwell test cards
• CPC Class Codes: G01N 2035/1034 Transferring microquantities of liquid
• CPC Class Codes: G01N 35/085 Flow Injection Analysis
• CPC Class Codes: G01N 35/1065 Multiple transfer devices
• CPC Class Codes: Y10T 29/494 Fluidic or fluid actuated device making

Abstract

A system, including method and apparatus, for generating droplets suitable for droplet-based assays. The disclosed systems may include either one-piece or multi-piece droplet generation components configured to form sample-containing droplets by merging aqueous, sample-containing fluid with a background emulsion fluid such as oil, to form an emulsion of sample-containing droplets suspended in the background fluid. In some cases, the disclosed systems may include channels or other suitable mechanisms configured to transport the sample-containing droplets to an outlet region, so that subsequent assay steps may be performed.

Claims

1. A device for generating droplets, the device comprising:

a body including a substrate and a plurality of protrusions, the substrate having a bottom side defining a channel network including a first channel, a second channel, and a third channel that meet one another at a droplet-generation region, the plurality of protrusions being formed integrally with the substrate and projecting from a top side of the substrate; and

a sealing member attached to the bottom side of the substrate in a fluid-tight seal and providing a bottom wall for each channel of the channel network;

wherein the device includes a carrier port configured to receive carrier fluid that flows from the carrier port to the droplet-generation region via the first channel;

wherein the device includes a sample well configured to receive sample-containing fluid that flows to the droplet-generation region via the second channel;

wherein the device includes a droplet well configured to receive sample-containing droplets and carrier fluid that flow from the droplet-generation region to the droplet well via the third channel; and

wherein each of the sample well and the droplet well has an upper portion created by a protrusion of the plurality of protrusions.

2. The device of claim 1, wherein the carrier port is provided by a carrier well.

3. The device of claim 2, wherein the carrier well has an upper portion created by a protrusion of the plurality of protrusions.

4. The device of claim 1, wherein the body is an injection-molded, one-piece body.

5. The device of claim 1, wherein the sealing member forms a bottom wall of the sample well and the droplet well.

6. The device of claim 1, wherein the sealing member is a substantially featureless film.

7. The device of claim 1, wherein the device includes another well that is in fluid communication with the droplet well via the channel network.

8. The device of claim 1, wherein the upper portion of the droplet well has a top rim.

9. The device of claim 1, wherein the second channel includes an air trap configured to prevent sample-containing fluid from being inadvertently drawn through the second channel by capillary action.

10. The device of claim 1, wherein the first channel includes two sub-channels that intersect the second channel from two different directions to form a cross-shaped intersection region with the second channel and the third channel.

11. The device of claim 10, wherein the two sub-channels have substantially equal hydraulic resistances.

12. The device of claim 1, further comprising a plurality of wells including the sample well and the droplet well, wherein an upper portion of each well of the plurality of wells is formed by a protrusion of the plurality of protrusions, and wherein the plurality of wells includes a row of sample wells and a row of droplet wells.

13. The device of claim 12, wherein a plurality of droplet-generation regions are defined by the bottom side of the substrate, wherein each sample well of the row of sample wells is configured to supply sample-containing fluid to a different droplet-generation region of the plurality of droplet-generation regions, and wherein each droplet well of the row of droplet wells is configured to receive droplets and carrier fluid from a different droplet-generation region of the plurality of droplet-generation regions.

14. The device of claim 12, wherein each row has exactly eight wells.

15. The device of claim 12, wherein the sealing member provides a bottom wall for each well of the plurality of wells.

16. A method of generating droplets with the device of claim 1, the method comprising:

placing sample-containing fluid into the sample well; and

creating a pressure differential after the step of placing to drive generation of sample-containing droplets at the droplet-generation region and travel of the sample-containing droplets and carrier fluid to the droplet well.