Manipulation of beads in droplets and methods for splitting droplets

• US 8,470,606 B2
• Filed: 04/15/2010
• Issued: 06/25/2013
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: Duke University
• Original Assignee: Duke University, Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Inventors: Srinivasan, Vijay, Pamula, Vamsee K., Pollack, Michael G., Fair, Richard B.
• Primary Examiner(s): Sines, Brian J
• Application Number:
  US12/761,147
• Publication Number:
  US 20100258441A1
• Time in Patent Office: 1,167 Days
• Field of Search: 422/82.01, 422/82.02, 422/100, 422/50, 422/68.1, 422/502, 422/503, 422/504, 436/43, 436/149, 436/150, 436/174, 436/179, 436/180
• US Class Current: 436/180
• CPC Class Codes: B01F 31/65 the materials to be mixed being directly submitted to a pulsating movement, e.g. by means of an oscillating piston or air column
• CPC Class Codes: B01F 33/3021 the components to be mixed being combined in a single independent droplet, e.g. these droplets being divided by a non-miscible fluid or consisting of independent droplets
• CPC Class Codes: B01F 33/3031 using electro-hydrodynamic [EHD] or electro-kinetic [EKI] phenomena to mix or move the fluids
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• 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 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• 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 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0421 electrophoretic flow
• 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 2400/0436 acoustic forces, e.g. surface acoustic waves [SAW]
• CPC Class Codes: B01L 2400/0442 thermal energy, e.g. vaporisation, bubble jet
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• 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 3/502792 : for moving individual droplets on a plate, e.g. by locally altering surface tension
• 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: G01N 2035/1046 : Levitated, suspended drops
• 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 436/11 : Automated chemical analysis
• CPC Class Codes: Y10T 436/25 : including sample preparation
• CPC Class Codes: Y10T 436/25625 : Dilution
• CPC Class Codes: Y10T 436/2575 : Volumetric liquid transfer

Abstract

The invention provides a method of circulating magnetically responsive beads within a droplet in a droplet actuator. The invention also provides methods for splitting droplets. The invention, in one embodiment, makes use of a droplet actuator with top and bottom substrates, a plurality of magnetic fields respectively present proximate the top and bottom substrates, wherein at least one of the magnet fields is selectively alterable, and a plurality of droplet operations electrodes positioned along at least one of the top and bottom surfaces. A droplet is positioned between the top and bottom surfaces and at least one of the magnetic fields is selectively altered.

Claims

1. A method of splitting a droplet comprising a magnetically responsive bead in a droplet actuator, the method comprising:

(a) providing a droplet actuator comprising;

(i) a plurality of droplet operations electrodes configured to transport the droplet; and

(ii) one or more magnets to generate a magnetic field present at the plurality of droplet operations electrodes;

(b) providing a magnetically responsive bead-containing droplet on the droplet actuator;

(c) immobilizing the magnetically responsive bead using the magnetic field; and

(d) using the plurality of droplet operations electrodes to split the droplet into first and second droplets, wherein the magnetically responsive bead remains substantially immobilized.