Advanced Liquid Logic, Inc.

Duke University

Ramakrishna Sista

Vamsee K Pamula

Michael G Pollack

Vijay Srinivasan

Arjun Sudarsan

Allen E Eckhardt

Prasanna Krishnan Thwar

Richard B Fair

Alexander Shenderov

Zhishan Hua

Theodore M Winger

Dwayne J Allen

William Craig Bauer

Carrie A Graham

Donovan E Bort

Gajendrasinh Raolji

Raveendra Dayam

Tong Wang

Yalin Xiong

Ning Wu

Sanjay Saha

Gajendrasinh Balvantsinh Raolji

Carrie Graham

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.

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 of concentrating beads in a droplet and/or loading beads on a fluidic device are provided, including among other things, a method of concentrating beads in a droplet, the method comprising: (a) providing a droplet actuator comprising: (i) an interior droplet operations volume; and (ii) a reservoir exterior to the interior volume; (iii) a droplet established in a liquid path extending from the reservoir into the interior volume; (b) providing magnetically responsive beads in the portion of the droplet which is in the reservoir; (c) magnetically attracting the magnetically responsive beads through the liquid path into the portion of the droplet which is in the interior volume; and (d) forming a droplet comprising one or more of the magnetically responsive beads in the interior volume.

Method of concentrating beads in a droplet

The invention is directed to droplet actuator devices and assay methods. The invention includes assay methods of conducting an assay comprising combining a sample with an umbelliferyl derivative, wherein the sample potentially comprises an enzyme capable of cleaving the umbelliferyl derivative and where the umbelliferyl derivative comprises an umbelliferyl core modified with one or more modifying moieties.

Enzyme assays on a droplet actuator

Droplet actuator apparatus and system are provided. An apparatus comprises: a microfluidics system having an insertion slot for insertion of a droplet actuator; a bottom plate against which the droplet actuator would slide when inserting the droplet actuator into the insertion slot; and means for forcing a substrate in the droplet actuator parallel to the bottom plate, wherein warpage in the substrate is corrected.

Droplet actuator apparatus and system

The invention provides a method of redistributing magnetically responsive beads in a droplet. The method may include conducting on a droplet operations surface one or more droplet operations using the droplet without removing the magnetically responsive beads from the region of the magnetic field. The droplet operations may in some cases be electrode-mediated. The droplet operations may redistribute and/or circulate the magnetically responsive beads within the droplet. In some cases, the droplet may include a sample droplet may include a target analyte. The redistributing of the magnetically responsive beads may cause target analyte to bind to the magnetically responsive beads. In some cases, the droplet may include unbound substances in a wash buffer. The redistributing of the magnetically responsive beads causes unbound substances to be freed from interstices of an aggregated set or subset of the magnetically responsive beads.

Growing community of inventors

Morrisville, NC, United States of America

Ramakrishna Sista