Abstract: The present 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: Multiwell droplet actuators, systems and methods are provided. According to one embodiment, a substrate is provided and comprises: (a) one or more input ports for introduction of one or more reagents and/or samples; (b) a regular array of processing wells; and (c) a network of droplet transport pathways comprising pathways that provide direct or indirect droplet transport from each of the input ports to each of the one or more processing wells. Varying droplet actuators and systems related thereto are also provided.

Abstract: The present invention relates to droplet-based particle sorting. According to one embodiment, a droplet microactuator is provided and includes: (a) a suspension of particles; and (b) electrodes arranged for conducting droplet operations using droplets comprising particles. A method of transporting a particle is also provided, wherein the method includes providing a droplet comprising the particle and transporting the droplet on a droplet microactuator.

Abstract: The present invention provides droplet actuators, modified fluids and methods relating to droplet operations. An aspect includes a droplet actuator including a droplet operations substrate; an oil based filler fluid on the droplet operations substrate comprising an oil soluble additive in the filler fluid; and a droplet in contact with the oil based filler fluid. Still other aspects are provided.

Abstract: The invention provides a method of redistributing magnetically responsive beads in a droplet. The method may include providing a droplet including magnetically responsive beads. The droplet may be provided within a region of a magnetic field having sufficient strength to attract the magnetically responsive beads to an edge of the droplet or towards an edge of the droplet, or otherwise regionalize or aggregate beads within the droplet. The method may also 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.

Abstract: The invention is directed to droplet actuator devices and assay methods. The method may include, among other things, a method of conducting enzymatic assays using umbelliferone substrates with cyclodextrins in droplets in oil, the method including incubating a droplet in oil, the droplet preferably comprising an umbelliferone substrate, a sample, and a cyclodextrin compound. The methods may further include a method of substantially eliminating cross-contamination between droplets in enzymatic containing substrate-based bioassays. The method may include immobilization of the enzymatic substrate including forming an inclusion complex with the substrate for stabilizing the substrate within an aqueous environment, wherein the inclusion complex may be formed using cyclodextrins. In yet another embodiment, the invention may provide a method of enhancing hydrolysis of enzymatic substrates.

Abstract: A series of microactuators for manipulating small quantities of liquids, and methods of using these for manipulating liquids, are disclosed. The microactuators are based on the phenomenon of electrowetting and contain no moving parts. The force acting on the liquid is a potential-dependent gradient of adhesion energy between the liquid and a solid insulating surface.

Abstract: A droplet actuator with cartridge is provided. According to one embodiment, a sample analyzer is provided and includes an analyzer unit comprising electronic or optical receiving means, a cartridge comprising self-contained droplet handling capabilities, and a wherein the cartridge is coupled to the analyzer unit by a means which aligns electronic and/or optical outputs from the cartridge with electronic or optical receiving means on the analyzer unit. According to another embodiment, a sample analyzer is provided and includes a sample analyzer comprising a cartridge coupled thereto and a means of electrical interface and/or optical interface between the cartridge and the analyzer, whereby electrical signals and/or optical signals may be transmitted from the cartridge to the analyzer.

Abstract: The invention provides techniques for coagulating blood on a droplet actuator. The invention also provides methods of manipulating the coagulated blood including a variety of droplet operations that may be conducted using the coagulated blood. Further, the invention provides a variety of assays that make use of the coagulated blood or various blood samples as input.

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: The present invention relates to a droplet-based nucleic acid amplification apparatus and system. According to one embodiment, a droplet microactuator is provided made using a first substrate including a fluorescing material and including a detection region for detecting a fluorescence signal from a droplet, which detection region is coated with a light absorbing, low fluorescence or non-fluorescing material.

Abstract: 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.

Abstract: The invention relates to certain novel approaches to reducing or eliminating the movement of contaminants from one droplet to another on a droplet actuator via liquid filler fluid. In one application, droplet actuators are used to conduct genetic analysis using polymerase chain reaction (PCR) techniques. The invention addresses the need for improved methods of performing PCR on a droplet actuator that provide for optimum amplification and detection of a sample target.

Abstract: The invention provides droplet actuators and droplet actuator techniques. Among other things, the droplet actuators and methods are useful for manipulating beads on a droplet actuator, such as conducting droplet operations using bead-containing droplets on a droplet actuator. For example, beads may be manipulated on a droplet actuator in the context of executing a sample preparation protocol and/or an assay protocol. An output of the methods of the invention may be beads prepared for execution of an assay protocol. Another output of the methods of the invention may be results of an assay protocol executed using beads.

Abstract: A droplet actuator comprising: (a) a base substrate comprising electrodes configured for conducting droplet operations on a droplet operations surface thereof; (b) a droplet comprising one or more beads situated on the droplet operations surface; (c) a barrier arranged in relation to the droplet and the electrodes such that a droplet may be transported away from the beads using one or more droplet operations mediated by one or more of the electrodes while transport of the beads is restrained by a barrier. Related methods and kits are also provided.

Abstract: Methods of improving microfluidic assays are disclosed. Assays can be improved (better signal to noise ratio) by using sessile drop evaporation as an analyte concentration step (enhanced signal) and repeated passes of wash droplets as a means to reduce non-specific binding (noise reduction). In addition multiple massively parallel analyses improve the statistical precision of the analyses.

Abstract: The present invention relates to droplet-based particle sorting. According to one embodiment, a droplet microactuator is provided and includes: (a) a suspension of particles; and (b) electrodes arranged for conducting droplet operations using droplets comprising particles. A method of transporting a particle is also provided, wherein the method includes providing a droplet comprising the particle and transporting the droplet on a droplet microactuator.

Abstract: A method of amplifying a nucleic acid, the method comprising cycling an amplification-ready droplet through a temperature gradient to locations within the temperature gradient suitable for effecting steps in an amplification reaction.

Abstract: The present invention relates to a droplet-based nucleic acid amplification method and apparatus.

Abstract: Droplet actuators for conducting droplet operations, such as droplet transport and droplet dispensing, are provided. In one embodiment, the droplet actuator may include a substrate including, droplet operations electrodes arranged for conducting droplet operations on a surface of the substrate; and reference electrodes associated with the droplet operations electrodes and extending above the surface of the substrate. Other embodiments of droplet actuators and methods of loading and using such droplet actuators are also provided.