A method of digital quantification of a species in an EWOD device includes inputting a sample volume and a diluent volume into the EWOD device; performing an electrowetting operation to generate a first sample droplet from the sample volume; performing an amplification process on the first sample droplet and measuring a turn-on value for the sample droplet; comparing the measured turn-on value to a target turn-on value for digital quantification; calculating a dilution factor based on the comparison of the measured and target turn-on values; performing an electrowetting operation to extract a second sample droplet from the sample volume; performing an electrowetting operation to dilute the second sample droplet with the diluent volume by the dilution factor to form a diluted second sample droplet; and performing a digital quantification on the diluted second sample droplet to quantify an initial concentration of the species in the sample volume.

Disclosed are devices and methods useful for confined-channel digital microfluidics that combine high-throughput droplet generators with digital microfluidic for droplet manipulation. The present disclosure also provides an off-chip sensing system for droplet tracking.

Systems and methods for continuous flow polymerase chain reaction (PCR) are provided. The system comprises an injector, a mixer, a coalescer, a droplet generator, a detector, a digital PCR system, and a controller. The injector takes in a sample, partitions the sample into sample aliquots with the help of an immiscible oil phase, dispenses waste, and sends the sample aliquot to the mixer. The mixer mixes the sample aliquot with a PCR master mix and diluting water, dispenses waste, and sends the sample mixture (separated by an immiscible oil) to the coalescer. The coalescer coalesces the sample mixture with primers dispensed from a cassette, dispenses waste, and sends the reaction mixture (separated by an immiscible oil) to the droplet generator. The droplet generator converts the sample mixture into an emulsion where aqueous droplets of the reaction mixture are maintained inside of an immiscible oil phase and dispenses droplets to the digital PCR system. The digital PCR system amplifies target DNAs in the droplets. The detector detects target DNAs in the droplets. The controller controls the system to run automatically and continuously.

The present invention generally relates to systems and methods for the control of fluids and, in some cases, to systems and methods for flowing a fluid into and/or out of other fluids. As examples, fluid may be injected into a droplet contained within a fluidic channel, or a fluid may be injected into a fluidic channel to create a droplet. In some embodiments, electrodes may be used to apply an electric field to one or more fluidic channels, e.g., proximate an intersection of at least two fluidic channels. For instance, a first fluid may be urged into and/or out of a second fluid, facilitated by the electric field. The electric field, in some cases, may disrupt an interface between a first fluid and at least one other fluid. Properties such as the volume, flow rate, etc. of a first fluid being urged into and/or out of a second fluid can be controlled by controlling various properties of the fluid and/or a fluidic droplet, for example curvature of the fluidic droplet, and/or controlling the applied electric field.

The invention provides a device, method, and system for high throughput detection of nucleic acid expression in individual cells. Cells are encapsulated in aqueous microdroplets which are merged with a biocompatible matrix, allowing on-chip fluorescence in situ hybridization on both adherent and non-adherent cells. The invention also provides multiplexed detection of nucleic acids, proteins, and cellular activity. The device and methods can be used to assess cellular interactions and to test the effects of antitumor agents.

The present invention relates to droplet-based surface modification and washing. According to one embodiment, a method of splitting a droplet is provided, the method including providing a droplet microactuator including a droplet including one or more beads and immobilizing at least one of the one or more beads. The method further includes conducting one or more droplet operations to divide the droplet to yield a set of droplets including a droplet including the one or more immobilized beads and a droplet substantially lacking the one or more immobilized beads.

Microfluidic methods for barcoding nucleic acid target molecules to be analyzed, e.g., via nucleic acid sequencing techniques, are provided. Also provided are microfluidic, droplet-based methods of preparing nucleic acid barcodes for use in various barcoding applications. The methods described herein facilitate high-throughput sequencing of nucleic acid target molecules as well as single cell and single virus genomic, transcriptomic, and/or proteomic analysis/profiling. Systems and devices for practicing the subject methods are also provided.

The invention provides methods for assessing one or more predetermined characteristics or properties of a microfluidic droplet within a microfluidic channel, and regulating one or more fluid flow rates within that channel to selectively alter the predetermined microdroplet characteristic or property using a feedback control.

The present invention generally relates to systems and methods for the control of fluids and, in some cases, to systems and methods for flowing a fluid into and/or out of other fluids. As examples, fluid may be injected into a droplet contained within a fluidic channel, or a fluid may be injected into a fluidic channel to create a droplet. In some embodiments, electrodes may be used to apply an electric field to one or more fluidic channels, e.g., proximate an intersection of at least two fluidic channels. For instance, a first fluid may be urged into and/or out of a second fluid, facilitated by the electric field. The electric field, in some cases, may disrupt an interface between a first fluid and at least one other fluid. Properties such as the volume, flow rate, etc. of a first fluid being urged into and/or out of a second fluid can be controlled by controlling various properties of the fluid and/or a fluidic droplet, for example curvature of the fluidic droplet, and/or controlling the applied electric field.

An electrowetting panel includes a base substrate; an electrode array layer, including a plurality of electrodes arranged into an array; an insulating hydrophobic layer; a microfluidic channel layer located on the base substrate. Each electrode of the plurality of electrodes is connected to a driving circuit, and a droplet can move along a first direction by applying an electric voltage on each electrode. The insulating hydrophobic layer is located on the electrode array layer, and the microfluidic channel layer is located on the insulating hydrophobic layer. The electrodes includes a plurality of driving electrodes and a plurality of detecting electrodes. Along the first direction, a number N of the driving electrodes is located between every two adjacent detecting electrodes, where N is a natural number. The electrowetting panel also includes a detecting chip electrically connected to the detecting electrodes.