Abstract:
Droplet actuator for conducting droplet operations, such as droplet transport and droplet dispensing, is provided. In one embodiment, the droplet actuator may include an electrode that is rotationally but not reflectively symmetrical.
Abstract:
A method of detecting a target analyte in a sample, including executing electrowetting-mediated droplet operations and thereby: combining one or more immunoassay reagent droplets comprising magnetically-responsive beads having affinity for the target analyte with one or more sample droplets potentially comprising the target analyte to yield a first combined droplet; beginning with the combined droplet, effecting a droplet-based washing protocol to wash the magnetically-responsive beads to yield a first washed droplet comprising the washed magnetically responsive beads; and combining the droplet comprising the washed magnetically responsive beads with a droplet comprising a reporter molecule having affinity for target analyte captured on the magnetically-responsive beads to yield a second combined droplet; beginning with the second combined droplet, effecting a droplet-based washing protocol to wash the magnetically-responsive beads to yield a second washed droplet comprising the washed magnetically responsive beads; detecting a signal from the second washed droplet which corresponds to the presence, absence and/or quantity of the analyte in the sample.
Abstract:
Methods of improving accuracy of droplet metering using at least one on-actuator reservoir as the fluid input. In some embodiments, the on-actuator reservoir that is used for metering droplets includes a loading port, a liquid storage zone, a droplet metering zone, and a droplet dispensing zone. The on-actuator reservoirs are designed to prevent liquid flow-back into the loading port and to prevent liquid from flooding into the droplet operations gap in the dispensing zone.
Abstract:
The present invention is directed to methods of improving accuracy of droplet metering using at least one on-actuator reservoir as the fluid input. In some embodiments, the on-actuator reservoir that is used for metering droplets includes a loading port, a liquid storage zone, a droplet metering zone, and a droplet dispensing zone. The on-actuator reservoirs are designed to prevent liquid flow-back into the loading port and to prevent liquid from flooding into the droplet operations gap in the dispensing zone.
Abstract:
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.
Abstract:
During droplet operations in a droplet actuator, bubbles often form in the filler fluid in the droplet operations gap and interrupt droplet operations. The present invention provides methods and systems for performing droplet operations on a droplet in a droplet actuator comprising maintaining substantially consistent contact between the droplet and an electrical ground while conducting multiple droplet operations on the droplet in the droplet operations gap and/or reducing the accumulation of electrical charges in the droplet operations gap during multiple droplet operations. The methods and systems reduce or eliminate bubble formation in the filler fluid of the droplet operations gap, thereby permitting completion of multiple droplet operations without interruption by bubble formation in the filler fluid in the droplet operations gap.
Abstract:
A method of manipulating a droplet comprising providing a substrate comprising a surface; an elongated transport electrode disposed on the substrate surface, the elongated transport electrode having a first and a second end and configured to impart a gradient force to the droplet; and one or more wires for providing power to the transport electrode; and providing power to the one or more wires to effect the gradient force and thereby transport the droplet along the length of the elongated transport electrode from the first end to the second end.
Abstract:
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.
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.
Abstract:
A droplet actuator with a droplet formation electrode configuration associated with a droplet operations surface, wherein the electrode configuration comprises 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.