Abstract: Provided herein are methods, systems and digital microfluidic cartridges for the determination of ligand-target analyte affinity value (KD), determination of an association rate constant (kon), and/or determination of a dissociation rate constant (koff) in a PR (plasmon resonance) based system. More specifically, as described herein, the present disclosure is directed to improved methods, systems and digital microfluidic cartridges for determining a dissociation rate constant (koff) using free ligand molecules in the dissociation phase or dissociation step of a standard kinetic binding curve or in ligand-target analyte affinity analysis (referred to herein as ligand assisted dissociation (LAD)).

Abstract: A pipette dispenser vision system and method are disclosed. For example, a pipette dispenser vision system is provided for tracking pipettes with respect to dispensing liquid into target fluid wells, vessels, and/or reservoirs. The presently disclosed pipette dispenser vision system may include, for example, a computing device, a red/green/blue (RGB) imaging device, an infrared (IR) imaging device, an IR illumination source, and an IR sensor; all arranged with respect to, for example, a single-channel and/or a multi-channel pipette for dispensing liquid into a dispensing platform. Further, a method of using the presently disclosed pipette dispenser vision system is provided. For example, the method processes image data from the RGB imaging device and/or the IR imaging device to monitor/verify certain operations of the pipetting process and/or dispensing platform.

Abstract: A pipette dispenser vision system and method are disclosed. For example, a pipette dispenser vision system is provided for tracking pipettes with respect to dispensing liquid into target fluid wells, vessels, and/or reservoirs. The presently disclosed pipette dispenser vision system may include, for example, a computing device, a red/green/blue (RGB) imaging device, an infrared (IR) imaging device, an IR illumination source, and an IR sensor; all arranged with respect to, for example, a single-channel and/or a multi-channel pipette for dispensing liquid into a dispensing platform. Further, a method of using the presently disclosed pipette dispenser vision system is provided. For example, the method processes image data from the RGB imaging device and/or the IR imaging device to monitor/verify certain operations of the pipetting process and/or dispensing platform.

Abstract: A cartridge with (a) a top substrate and a bottom substrate separated to form a droplet operations gap, the top substrate comprising a well plate comprising an array of wells each well comprising a hollow needle liquidly connecting an interior of the well with the droplet operations gap; and (b) a compressible membrane layer atop the well plate sealing the reservoirs and arranged so that compression of the flexible membrane towards the interior of the well forces a liquid from the interior of the well through the hollow needle, and into the droplet operations gap.

Abstract: A pipette dispenser vision system and method are disclosed. For example, a pipette dispenser vision system is provided for tracking pipettes with respect to dispensing liquid into target fluid wells, vessels, and/or reservoirs. The presently disclosed pipette dispenser vision system may include, for example, a computing device, a red/green/blue (RGB) imaging device, an infrared (IR) imaging device, an IR illumination source, and an IR sensor; all arranged with respect to, for example, a single-channel and/or a multi-channel pipette for dispensing liquid into a dispensing platform. Further, a method of using the presently disclosed pipette dispenser vision system is provided. For example, the method processes image data from the RGB imaging device and/or the IR imaging device to monitor/verify certain operations of the pipetting process and/or dispensing platform.

Abstract: The present disclosure provides a digital microfluidic (DMF) cartridge for performing a self-test for a target analyte, including a DMF cartridge comprising a bottom substrate and a top substrate separated by a droplet operations gap, wherein the bottom substrate comprises a plurality of droplet operations electrodes configured for performing droplet operations on a liquid droplet in the droplet operations gap; one or more reaction chambers or reaction zones on the bottom substrate that are supplied by an arrangement of the droplet operations electrodes, wherein each reaction chamber or reaction zone comprises at least one detection spot and is configured for performing a plasmonic particle-assisted ELISA (pELISA) for detection and quantification of a target analyte in a sample droplet. The device may include downloadable software for a self-test and be operable using a smart device.

Abstract: 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.

Abstract: 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.

Abstract: A plasmon resonance (PR) system and instrument, digital microfluidic (DMF) cartridge, and methods of using localized surface plasmon resonance (LSPR) and droplet operations for analysis of analytes is disclosed. For example, a PR system is provided that may include a DMF cartridge that may support both fixed LSPR sensing capability and in-solution LSPR sensing capability for analysis of analytes. The DMF cartridge may include an electrode arrangement for performing droplet operations, wherein the droplet operations can be used for performing fixed LSPR sensing operations and in-solution LSPR sensing operations. Further, methods of using droplet operations in the DMF cartridge to perform fixed LSPR sensing operations and/or in-solution LSPR sensing operations are provided.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A droplet actuator with a droplet formation electrode configuration associated with a droplet operations surface, wherein the electrode configuration may include one or more electrodes configured to control volume of a droplet during formation of a sub-droplet on the droplet operations surface. Methods of making and using the droplet actuator are also provided.

Abstract: The invention provides droplet actuators with droplet operations surfaces for manipulating droplets, e.g., by conducting droplet operations. The droplet operations surfaces are typically exposed to a droplet operations gap. One or more regions of a droplet operation surface may include patterned topographic features. The invention also provides a droplet actuator in which one or both gap-facing droplet operations surfaces is formed using a removable film. The removable film may, in various embodiments, also include other components ordinarily associated with the droplet actuator substrate, such as the dielectric layer and the electrodes. Further, the invention provides droplet actuator devices and methods for coupling and/or sealing substrates of a droplet actuator, such as techniques for self-aligning assembly of droplet actuator substrates.

Abstract: The invention provides a droplet actuator. The droplet actuator may include a base substrate and a top substrate separated to form a gap. The base substrate may include electrodes configured for conducting droplet operations in the gap; and the top substrate may include a glass substrate portion coupled to a non-glass portion, where the non-glass portion may include one or more openings establishing a fluid path extending from an exterior of the droplet actuator and into the gap. The invention also provides related methods of manufacturing the droplet actuator, methods of using the droplet actuator, and methods of loading the droplet actuator.

Abstract: Methods comprising measuring the impedance of the electrode produced by the excitation signal, wherein the impedance indicates presence of liquid at the electrode are disclosed. Computer readable mediums storing processor executable instructions for performing the method, and systems are also disclosed. The systems comprise a processor, memory and code stored in the memory that when executed cause the processor at least to: receive an output voltage signal, superimpose an excitation signal onto the output voltage signal to produce a superimposed signal, connect the superimposed signal to an electrode in a droplet actuator, suppress the output voltage signal, when detecting an impedance of the electrode, and measure the impedance of the electrode produced by the excitation signal, wherein the impedance indicates presence of liquid at the electrode.