Manipulating droplet size

• US 8,658,430 B2
• Filed: 07/20/2012
• Issued: 02/25/2014
• Est. Priority Date: 07/20/2011
• Status: Active Grant

• Current Assignee: Bio-Rad Laboratories Incorporated
• Original Assignee: Raindance Technologies Incorporated (Bio-Rad Laboratories Incorporated)
• Inventors: Miller, Benjamin J., Zhong, Qun, Link, Darren Roy
• Primary Examiner(s): COLE, MONIQUE T
• Application Number:
  US13/554,655
• Publication Number:
  US 20130099018A1
• Time in Patent Office: 585 Days
• Field of Search: 436/180
• US Class Current: 436/180
• 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: B01F 35/2213 Pressure
• CPC Class Codes: B01L 2200/025 Align devices or objects to ensure defined positions relative to each other
• CPC Class Codes: B01L 2200/0647 Handling flowable solids, e.g. microscopic beads, cells, particles
• CPC Class Codes: B01L 2200/141 Preventing contamination, tampering
• CPC Class Codes: B01L 2200/143 Quality control, feedback systems
• CPC Class Codes: B01L 2200/148 Specific details about calibrations
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/14 Means for pressure control
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• 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 7/525 with physical movement of samples between temperature zones
• CPC Class Codes: B05B 1/02 designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shapeB05B1/26, B05B1/28, B05B1/34 take precedence
• CPC Class Codes: B05B 1/08 of pulsating nature, e.g. delivering liquid in successive separate quantities ; Fluidic oscillators
• CPC Class Codes: B05B 1/26 with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets
• CPC Class Codes: B05B 7/0012 Apparatus for achieving spraying before discharge from the apparatus
• 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: Y10T 436/2575 Volumetric liquid transfer

Abstract

The invention generally relates to methods and systems for manipulating droplet size. In certain aspects, the invention provides methods for manipulating droplet size that include forming droplets of aqueous fluid surrounded by an immiscible carrier fluid, and manipulating droplet size during the forming step by adjusting pressure exerted on the aqueous fluid or the carrier fluid.

Claims

1. A method for droplet formation, the method comprising the steps of:

providing a plurality of aqueous fluids each in its own aqueous fluid channel in fluid communication with one or more immiscible carrier fluid channels;

forming droplets of aqueous fluid surrounded by an immiscible carrier fluid in the aqueous fluid channels;

applying a same constant pressure to the carrier fluid in each of the immiscible carrier fluid channels; and

adjusting pressure in one or more of the aqueous fluid channels, thereby to produce droplets of aqueous fluid in one or more outlet fluid channels.

2. The method of claim 1, wherein the same constant pressure derives from pressure in a reservoir in fluid communication with each of the carrier fluid channels.

3. The method of claim 1, wherein the same constant pressure is applied by a single pressure source to each of the carrier fluid channels.

4. The method of claim 3, wherein the pressure source comprises carrier oil.

5. The method of claim 1, wherein the droplets comprising a first aqueous fluid and the droplets comprising a second aqueous fluid are substantially uniform in size.

6. The method of claim 1, wherein the droplets comprising a first aqueous fluid are a different size than the droplets comprising a second aqueous fluid.

7. The method of claim 5 or 6, further comprising the step of detecting the size of the droplets in one or more of the aqueous fluid channels.

8. The method of claim 7, further comprising the step of changing the pressure applied to the carrier fluid and/or the pressure applied to the one or more of the aqueous fluid channels based on the detecting step.

9. The method of claim 6, further comprising the step of changing the pressure applied to a first of the aqueous fluid channels based on the detecting step, thereby to change the size of the droplets in the first aqueous fluid channel and not in other aqueous fluid channels.

10. The method of claim 1, wherein pressure is not regulated in at least one of the aqueous carrier channels.

11. The method of claim 1, wherein pressure is regulated in only one of the plurality of aqueous fluid channels.

12. The method of claim 1, wherein the immiscible carrier fluid is an oil.

13. The method of claim 12, wherein the oil comprises a surfactant.

14. The method of claim 13, wherein the surfactant is a fluorosurfactant.

15. The method of claim 1, wherein the aqueous fluid comprises nucleic acid and reagents for conducting an amplification reaction.

16. The method of claim 15, wherein the amplification reaction is a PCR reaction.

17. The method of claim 1, wherein said aqueous fluid channels comprise a plurality of microfluidic circuits, each of which comprises an independent aqueous fluid channel and wherein all members of said plurality of microfluidic circuits comprise a common immiscible carrier fluid channel.