Advanced Liquid Logic, Inc.

Duke University

Leland Stanford Junior University

Michael G Pollack

Vamsee K Pamula

Vijay Srinivasan

Richard B Fair

Allen E Eckhardt

Philip Y Paik

Ramakrishna Sista

Arjun Sudarsan

Alexander Shenderov

Zhishan Hua

Ryan A Sturmer

Dwayne J Allen

Prasanna Krishnan Thwar

Hong Ren

Peter B Griffin

Gregory F Smith

Michael Hauser

Keith R Brafford

Hon Lung Chu

Tih-Hong Wang

Jennifer Foley

Richard M West

Lavern Pope

Stefan Burde

Alexander D Shenderov

The present invention relates to droplet-based surface modification and washing. According to one embodiment, a method of splitting a droplet is provided, the method including providing a droplet microactuator including a droplet including one or more beads and immobilizing at least one of the one or more beads. The method further includes conducting one or more droplet operations to divide the droplet to yield a set of droplets including a droplet including the one or more immobilized beads and a droplet substantially lacking the one or more immobilized beads.

Droplet-based surface modification and washing

A method comprising effecting a change in a shape of a droplet, wherein the droplet is disposed over a substrate in sensing proximity to a sensor and the droplet has a starting surface area exposed to the sensor; and producing an expanded surface area of the droplet in the sensing proximity exposed to the sensor, wherein the expanded surface area exposed to the sensor is greater than the starting surface area exposed to the sensor.

Droplet actuator devices and methods employing magnetic beads

Provided herein are methods of splitting droplets containing magnetically responsive beads in a droplet actuator. A droplet actuator having a plurality of droplet operations electrodes configured to transport the droplet, and a magnetic field present at the droplet operations electrodes, is provided. The magnetically responsive beads in the droplet are immobilized using the magnetic field and the plurality of droplet operations electrodes are used to split the droplet into first and second droplets while the magnetically responsive beads remain substantially immobilized.

Manipulation of beads in droplets and methods for manipulating droplets

Methods are provided for separating magnetically responsive beads from a droplet in a droplet actuator. Droplet operations electrodes and a magnet are arranged in a droplet actuator to manipulate a bead-containing droplet and position it relative to a magnetic field region that attracts the magnetically responsive beads. The droplet operations electrodes are operated to control the droplet shape and transport it away from the magnetic field region to form a concentration of beads in the droplet. The continued transport of the droplet away from the magnetic field causes the concentration of beads to break away from the droplet to yield a small, concentrated bead-containing droplet immobilized by the magnet.

Bead incubation and washing on a droplet actuator

A method of providing a droplet in contact with a magnetically responsive bead and having a reduced quantity of a substance. The method generally includes the steps of (a) providing a droplet actuator comprising: (i) a substrate comprising electrodes arranged for conducting droplet operations on a surface; (ii) a starting droplet comprising: (1) one or more magnetically responsive beads; (2) a starting quantity of the substance; and (3) a starting volume; (b) magnetically immobilizing the one or more magnetically responsive beads at a location which is at a distance from a target droplet splitting zone; (c) conducting one or more droplet operations comprising droplet dividing operations selected to divide the combined droplet to yield a set of droplets comprising: (i) a droplet comprising substantially all of the one or more magnetically responsive beads and having a decreased quantity of the substance relative to the starting concentration; and (ii) a droplet substantially lacking the magnetically responsive beads.

A method, circuit and apparatus for detecting capacitance on a droplet actuator, inter alia, for determining the presence, partial presence or absence of a droplet at an electrode on a droplet actuator by: (a) providing a droplet actuator comprising: (i) a substrate comprising electrodes arranged on the substrate for conducting droplet operations on a surface of the substrate; (ii) a capacitance detection circuit for detecting capacitance at the droplet operations surface at one or more of the electrodes; (b) detecting capacitance at the droplet operations surface at one or more of the electrodes; and (c) determining from the capacitance the presence, partial presence or absence of a droplet at the droplet operations surface at the electrode.

Capacitance detection in a droplet actuator

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.

The invention relates to bead incubating and washing on a droplet actuator. Methods for incubating magnetically responsive beads that are labeled with primary antibody, a sample (i.e., analyte), and secondary reporter antibodies on a magnet, on and off a magnet, and completely off a magnet are provided. Also provided are methods for washing magnetically responsive beads using shape-assisted merging of droplets. Also provided are methods for shape-mediated splitting, transporting, and dispensing of a sample droplet that contains magnetically responsive beads. The apparatuses and methods of the invention provide for rapid time to result and optimum detection of an analyte in an immunoassay.

Methods are provided for manipulating droplets. The methods include providing the droplet on a surface comprising an array of electrodes and a substantially co-planer array of reference elements, wherein the droplet is disposed on a first one of the electrodes, and the droplet at least partially overlaps a second one of the electrodes and an intervening one of the reference elements disposed between the first and second electrodes. The methods further include activating the first and second electrodes to spread at least a portion of the droplet across the second electrode and deactivating the first electrode to move the droplet from the first electrode to the second electrode.

Droplet manipulation device

The invention is directed to a droplet actuator device and methods for integrating gel electrophoresis analysis with pre or post-analytical sample handling as well as other molecular analysis processes. Using digital microfluidics technology, the droplet actuator device and methods of the invention provide the ability to perform gel electrophoresis and liquid handling operations on a single integrated device. The integrated liquid handling operations may be used to prepare and deliver samples to the electrophoresis gel, capture and subsequently process products of the electrophoresis gel or perform additional assays on the same sample materials which are analyzed by gel electrophoresis. In one embodiment, one or more molecular assays, such as nucleic acid (e.g., DNA) quantification by real-time PCR, and one or more sample processing operations such as sample dilution is performed on a droplet actuator integrated with an electrophoresis gel. In one embodiment, an electrophoresis gel may be integrated on the top substrate of the droplet actuator.

Integrated droplet actuator for gel electrophoresis and molecular analysis

A liquid handling system for supplying liquids to a flow cell (FC). The system may include a droplet actuator cartridge, wherein the droplet actuator and a flow cell are fluidly coupled to, or situated within, a droplet operations gap of the droplet actuator.

Digital microfluidics cartridge and system for operating a flow cell

The invention provides droplet actuators and droplet actuator cassettes including reagent storage capabilities, as well as methods of making and using the droplet actuators and cassettes. The invention also provides continuous flow channel elements and techniques for using electrodes to manipulate droplets in flowing streams. The invention also discloses methods of separating compounds on a droplet actuator. Various other aspects of the invention are also disclosed.

Growing community of inventors

Durham, NC, United States of America

Michael G Pollack