System for transporting emulsions from an array to a detector

• US 9,623,384 B2
• Filed: 12/07/2010
• Issued: 04/18/2017
• Est. Priority Date: 09/23/2008
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Colston, Jr., Billy Wayne, Makarewicz, Jr., Anthony Joseph, Hindson, Benjamin Joseph, Ness, Kevin Dean, Milanovich, Fred Paul, Masquelier, Donald Arthur
• Primary Examiner(s): HOBBS, MICHAEL L
• Application Number:
  US12/962,511
• Publication Number:
  US 20110092373A1
• Time in Patent Office: 2,324 Days
• Field of Search: 4352872, 506 23, 506 40
• CPC Class Codes: B01F 2101/23 Mixing of laboratory samples e.g. in preparation of analysing or testing properties of materials
• CPC Class Codes: B01F 23/41 Emulsifying
• CPC Class Codes: B01F 23/4143 Microemulsions
• CPC Class Codes: B01F 23/4145 Emulsions of oils, e.g. fuel, and water
• 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: B01F 35/10 Maintenance of mixers
• CPC Class Codes: B01F 35/165 Making mixers or parts thereof
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2200/0689 Sealing
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/041 Connecting closures to device or container
• 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 2300/0819 Microarrays; Biochips
• CPC Class Codes: B01L 2300/0858 Side walls
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/1822 using Peltier elements
• CPC Class Codes: B01L 2400/0478 pistons
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/049 : vacuum
• CPC Class Codes: B01L 2400/0622 : distribution valves, valves having multiple inlets and/or outlets, e.g. metering valves, multi-way valves
• CPC Class Codes: B01L 3/0241 : Drop counters; Drop formers making arrays for combinatorial libraries B01J19/0046; automation of dispensing for analysis G01N35/10
• CPC Class Codes: B01L 3/502715 : characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• 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: B01L 7/525 : with physical movement of samples between temperature zones
• CPC Class Codes: B29C 2045/0079 : applying a coating or covering
• CPC Class Codes: B29C 45/0053 : combined with a final operation, e.g. shaping injection-compression moulding B29C45/561
• CPC Class Codes: B29C 45/006 : Joining parts moulded in separate cavities
• CPC Class Codes: B29L 2031/752 : Measuring equipment
• CPC Class Codes: C12Q 1/686 : Polymerase chain reaction [PCR]
• CPC Class Codes: G01N 2021/6439 : with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/3563 : for analysing solids; Preparation of samples therefor
• CPC Class Codes: G01N 21/49 : within a body or fluid
• CPC Class Codes: G01N 21/6428 : Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/6486 : Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

System, including apparatus and methods, for performing droplet-based assays. The system may comprise a droplet transporter configured to pick up droplets from each emulsion of an array of reacted emulsions and to drive flow of the droplets through a detection region. The system also may comprise a detector configured to collect data related to one or more analytes from individual droplets of the reacted emulsions as such individual droplets travel through the detection region. The system further may comprise a controller programmed to determine, based on the data collected, an aspect of the one or more analytes in one or more samples included in droplets of the emulsions.

Claims

1. A system for performing a droplet-based assay, comprising:

a droplet transporter including an inlet end, a channel junction, a source of carrier fluid including oil, and a detection region formed by a microfluidic channel, wherein the channel junction is connected to the inlet end, the source, and the detection region, wherein the inlet end is configured to be placed into each well of an array of wells, with each well holding an emulsion including a plurality of droplets disposed in a continuous phase, and wherein the droplet transporter is configured to (a) drive travel of droplets and the continuous phase of each emulsion into the inlet end and from the inlet end to the channel junction, (b) add carrier fluid from the source to the continuous phase at the channel junction, to spatially separate droplets from one another, and (c) drive travel of the spatially separated droplets through the detection region from the channel junction;

a detector configured to collect data related to one or more analytes from individual droplets of each emulsion as such individual droplets travel through the detection region; and

a processor programmed to analyze the data to determine (i) a number of droplets containing at least one copy of an analyte and/or a number of droplets containing no copies of the analyte, and (ii) a concentration of the analyte using at least one of the numbers.

2. The system of claim 1, wherein each emulsion is an amplified emulsion, and wherein the detector is configured to collect data related to amplification of at least one nucleic acid target in individual droplets of the emulsion.

3. The system of claim 2, wherein the processor is programmed to determine whether the at least one nucleic acid target is present or absent in each individual droplet based on the data collected.

4. The system of claim 1, wherein the droplet transporter includes an intake conduit that is connected to the detection region and that includes the inlet end, and wherein the droplet transporter is configured to dispose the inlet end of the intake conduit serially in the emulsions while such emulsions are held in the array of wells, to pick up droplets of each emulsion.

5. The system of claim 4, wherein the droplet transporter is configured to draw droplets of each emulsion into the intake conduit.

6. The system of claim 1, wherein the droplet transporter is configured to place a separating fluid between different emulsions picked up successively.

7. The system of claim 6, wherein the droplet transporter is configured to place air as the separating fluid.

8. The system of claim 7, wherein the droplet transporter is configured to draw air into the inlet end between contact of the inlet end with different emulsions.

9. The system of claim 6, wherein the droplet transporter is configured to draw a liquid comprising an oil into the inlet end between contact of the inlet end with different emulsions.

10. The system of claim 1, wherein the droplet transporter is configured to send droplets serially through the detection region.

11. The system of claim 1, wherein the detector includes a fluorescence detector.

12. The system of claim 1, wherein the droplet transporter is configured to drive relative movement of the inlet end and the array of wells along three orthogonal axes.

13. The system of claim 1, further comprising a plate that provides the array of wells.

14. The system of claim 13, wherein wells of the plate are spaced according to a well spacing of a standard microplate.

15. The system of claim 1, further comprising a thermocycler configured to thermally cycle the array of wells each holding an emulsion.

16. The system of claim 1, further comprising an array of wells that are connected to one another, wherein each well contains an emulsion including a plurality of droplets.