Method of making a device for generating droplets

• US 10,258,989 B2
• Filed: 11/30/2016
• Issued: 04/16/2019
• Est. Priority Date: 09/23/2008
• Status: Active Grant

• Current Assignee: Bio-Rad Laboratories Incorporated
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Ness, Kevin D., Hindson, Benjamin J., Colston, Jr., Billy W., Masquelier, Donald A.
• Primary Examiner(s): Hobbs, Michael L
• Application Number:
  US15/365,888
• Publication Number:
  US 20170144116A1
• Time in Patent Office: 867 Days
• 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

Methods of making a droplet-generating device. In an exemplary method, an upper member is injection molded. The upper member includes a bottom surface and also includes a first microfluidic channel, a second microfluidic channel, and a third microfluidic channel each formed in the bottom surface. The upper member has a plurality of openings each extending completely through the upper member from the bottom surface and creating a side wall region of a sample well, a carrier well, and a droplet well. A cover layer is attached to the bottom surface of the upper member, such that the cover layer seals a bottom side of each microfluidic channel. The microfluidic channels meet one another to create a droplet-generation region. The sample well, the carrier well, and the droplet well are connected to the droplet-generation region via the first, second, and third microfluidic channels, respectively.

Claims

1. A method of making a droplet-generating device, the method comprising:

injection molding an upper member including a bottom surface and also including a first microfluidic channel, a second microfluidic channel, and a third microfluidic channel each formed in the bottom surface and arranged parallel thereto, the upper member having a plurality of openings each extending completely through the upper member from the bottom surface, the openings creating a side wall region of a sample well, a carrier well, and a droplet well; and

attaching a cover layer to the bottom surface of the upper member, such that the cover layer seals a bottom side of each microfluidic channel;

wherein the microfluidic channels meet one another to create a droplet-generation region, and wherein the sample well is connected to the droplet-generation region via the first microfluidic channel, the carrier well is connected to the droplet-generation region via the second microfluidic channel, and the droplet well is connected to the droplet-generation region via the third microfluidic channel.

2. The method of claim 1, wherein the upper member is injection molded to include a base portion that provides the bottom surface of the upper member, and also to include a plurality of protrusions projecting upwardly from the base portion, and wherein each well has an upper portion formed by one of the protrusions.

3. The method of claim 2, wherein the upper member is injection molded such that each protrusion is annular.

4. The method of claim 2, wherein the cover layer is thinner than the base portion of the upper member.

5. The method of claim 1, wherein the cover layer is thinner than the upper member.

6. The method of claim 1, wherein each opening of the plurality of openings extends from a top side of the upper member to the bottom surface, and narrows at a position intermediate the top side and the bottom surface.

7. The method of claim 1, wherein the upper member is injection molded to have a fourth microfluidic channel formed in the bottom surface and arranged parallel thereto, wherein the second microfluidic channel and the fourth microfluidic channel extend separately to the droplet-generation region, and wherein the carrier well also is connected to the droplet-generation region via the fourth microfluidic channel.

8. A method of making a droplet-generating device, the method comprising:

injection molding an upper member as a single piece, the upper member having a base portion and also having a first microfluidic channel, a second microfluidic channel, and a third microfluidic channel each formed in a bottom surface of the base portion, the upper member including a plurality of protrusions projecting upwardly from the base portion, wherein one of the protrusions defines an upper portion of a sample well, another one of the protrusions defines an upper portion of a carrier well, and still another one of the protrusions defines an upper portion of a droplet well; and

attaching a cover layer to the bottom surface of the base portion, wherein the cover layer seals a bottom side of each microfluidic channel;

wherein the microfluidic channels meet one another in a droplet-generation region, and wherein the sample well is configured to supply sample-containing fluid to the droplet-generation region via the first microfluidic channel, the carrier well is configured to supply carrier fluid to the droplet-generation region via the second microfluidic channel, and the droplet well is configured to receive sample-containing droplets and carrier fluid from the droplet-generation region via the third microfluidic channel.

9. The method of claim 8, wherein the cover layer is thinner than the base portion.

10. The method of claim 8, wherein the upper member defines a respective opening corresponding to each well, wherein the opening extends completely through the upper member from a top side to the bottom surface of the upper member, and wherein the upper member is injection molded such that the opening is narrower at the bottom surface than the top side.

11. The method of claim 8, wherein the upper member is injection molded to have a fourth microfluidic channel formed in the bottom surface, wherein the second microfluidic channel and the fourth microfluidic channel extend separately to the droplet-generation region, and wherein the carrier well also is connected to the droplet-generation region via the fourth microfluidic channel.