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 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 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: 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: Protein crystallization droplet actuators, systems and methods are provided. According to one embodiment, a droplet actuator for providing an array of crystallization conditions is provided and includes: (a) two or more processing reservoirs; (b) two or more dispensing reservoirs collectively comprising two or more crystallization reagents; and (c) a port for introducing a sample for crystallization analysis. Systems including the droplet actuator, methods of providing an array of crystallization conditions, and methods of identifying crystallization conditions are also provided.

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: Protein crystallization screening and optimization droplet actuators, systems and methods are provided. According to one embodiment, a screening droplet actuator is provided and includes: (a) a port for introduction of one or more crystallization reagents and/or one or more protein solutions; and (b) a substrate including: (i) an array of two or more mixing wells; and (ii) electric field mediated microfluidics for moving droplets comprising the crystallization reagents and protein solutions into the mixing wells. Optimization droplet actuators, systems including screening droplet actuators, methods of screening protein crystallization conditions, and methods of testing conditions for growing a crystal are also provided.

Abstract: The present invention relates to a droplet-based nucleic acid amplification device, system, and method. According to one embodiment, a droplet microactuator is provided and includes: (a) a substrate comprising electrodes for conducting droplet operations; and (b) one or more temperature control means arranged in proximity with one or more of the electrodes for heating and/or cooling a region of the droplet microactuator and arranged such that a droplet can be transported on the electrodes into the region for heating.

Abstract: Systems for controlling a droplet microactuator are provided. According to one embodiment, a system is provided and includes a controller, a droplet microactuator electronically coupled to the controller, and a display device displaying a user interface electronically coupled to the controller, wherein the system is programmed and configured to permit a user to effect a droplet manipulation by interacting with the user interface. According to another embodiment, a system is provided and includes a processor, a display device electronically coupled to the processor, and software loaded and/or stored in a storage device electronically coupled to the controller, a memory device electronically coupled to the controller, and/or the controller and programmed to display an interactive map of a droplet microactuator.

Abstract: The present invention relates to droplet-based affinity assays. According to one embodiment, a method of detecting a target analyte in a sample is provided, wherein the method includes: (a) executing droplet operations to combine affinity-based assay reagents on a droplet microactuator with a sample potentially comprising the target analyte to generate a signal indicative of the presence, absence and/or quantity of analyte; and (b) detecting the signal, wherein the signal corresponds to the presence, absence and/or quantity of the analyte in the sample.

Abstract: Methods for amplifying nucleic acid, such as DNA or RNA, on a printed circuit board (PCB) substrate are disclosed. The amplification can be achieved through a variety of methods such as thermocycling or isothermally. The printed circuit board substrate can comprise an array of electrodes for transporting droplets and can be part of a sandwich structure including a top plate parallel to the printed circuit board substrate.

Abstract: Apparatuses for mixing droplets, such as a binary mixing apparatus, are provided. The binary mixing apparatus includes an array of electrodes and a conducting element positioned in relation to at least one of the electrodes to enable a droplet placed in electrical communication with the at least one electrode to electrically communicate with the conducting element. The binary mixing apparatus additionally includes an electrode selector for sequentially biasing one or more selected electrodes of the array to move a droplet disposed on the array into contact with another droplet. The apparatus further includes a first droplet supply area communicating with the array and a second droplet supply area communicating with the array.

Abstract: Methods for performing microfluidic sampling are provided. The method includes providing a substrate including an arrangement of first, second and third electrodes, wherein the second electrode is interposed between the first and third electrodes. The method additionally includes causing a fluid input to continuously flow to the first electrode and biasing the first, second and third electrodes to a first voltage to cause a portion of the fluid input to spread across the second and third electrodes. The method further includes biasing the second electrode to a second voltage different from the first voltage to form a droplet on the third electrode, the droplet being separate from the fluid input.

Abstract: Apparatuses and methods for manipulating droplets on a printed circuit board (PCB) are disclosed. Droplets are actuated upon a printed circuit board substrate surface by the application of electrical potentials to electrodes defined on the PCB. The use of soldermask as an electrode insulator for droplet manipulation as well techniques for adapting other traditional PCB layers and materials for droplet-based microfluidics are also disclosed.

Abstract: 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.