Abstract: Methods of partition-based analysis. In an exemplary method, a device having a port fluidically connected to a chamber may be selected. A sample-containing fluid may be placed into the port. The sample-containing fluid may be moved from the port to the chamber. Partitions of the sample-containing fluid may be formed. A monolayer of the partitions in the chamber may be created. At least a portion of the monolayer may be imaged.

Abstract: Methods of partition-based analysis. In an exemplary method, a device having a port fluidically connected to a chamber may be selected. A sample-containing fluid may be placed into the port. The sample-containing fluid may be moved from the port to the chamber. Partitions of the sample-containing fluid may be formed. A monolayer of the partitions in the chamber may be created. At least a portion of the monolayer may be imaged.

Abstract: Methods, devices, systems and compositions for detecting nucleic acids in polymerase chain reaction assays, such as droplet digital polymerase chain reaction (ddPCR) assays, using intercalating dyes. A dual surfactant system with at least one fluorosurfactant and at least one non-ionic non-fluorosurfactant may be employed for droplet generation and nucleic acid detection.

Abstract: Method of detecting a target nucleic acid. In an exemplary method, at least two thermal zones of different temperature may be created using a heating assembly. A first emulsion and a second emulsion may be formed. The first and second emulsions may be thermally cycled by passing them through tubing in a spaced relation to one another, with the tubing being wound around a central axis of the heating assembly and extending through each thermal zone multiple times. Thermally cycling may promote amplification of the target nucleic acid in droplets of each emulsion. Droplets of each emulsion may be passed through a detection channel located downstream of the tubing. Fluorescence may be detected from the droplets being passed through the detection channel.

Abstract: System, including methods and compositions, for making and using emulsions that include a silicone oil and a silicone surfactant. The emulsions may include aqueous droplets disposed in a continuous phase that includes a silicone oil and a silicone surfactant. The aqueous droplets may contain an analyte, optionally at partial occupancy, and/or a luminescent (e.g., photoluminescent) reporter. An assay of the analyte may be performed with the droplets. In some cases, signals may be detected from the droplets, and a characteristic of the analyte, such as an analyte level or activity, may be determined based on the signals.

Abstract: Method of detecting a signal from droplets for instrument calibration. In the method, a calibration standard for a droplet detection instrument may be received. The calibration standard may have been shipped at least one kilometer when received. The calibration standard may include a mixture of first droplets and second droplets. Each of the first and second droplets may be encapsulated by an immiscible carrier liquid and may have a stabilizing droplet skin that is formed by heating and that includes a skin-forming protein. Each the first droplets may contain a fluorescent dye, and each of the second droplets may contain a fluorescent dye. A fluorescence signal may be detected from a plurality of the first and second droplets with a droplet detection instrument. The fluorescence signal may be stronger for the first droplets than the second droplets.

Abstract: System, including methods and compositions, for making and using emulsions that include a silicone oil and a silicone surfactant. The emulsions may include aqueous droplets disposed in a continuous phase that includes a silicone oil and a silicone surfactant. The aqueous droplets may contain an analyte, optionally at partial occupancy, and/or a luminescent (e.g., photoluminescent) reporter. An assay of the analyte may be performed with the droplets. In some cases, signals may be detected from the droplets, and a characteristic of the analyte, such as an analyte level or activity, may be determined based on the signals.

Abstract: Devices and methods for generating droplets. An exemplary device comprises a substantially planar base portion including a bottom surface having a plurality of microfluidic channels formed therein as recessed regions of the bottom surface. The device also comprises a plurality of protrusions projecting from a top surface of the base portion and each formed integrally with the base portion. The device further comprises a sample well, a carrier well, and a droplet well. Each well has an upper portion created by one of the protrusions. A cover layer is attached to the bottom surface of the base portion and seals a bottom side of each microfluidic channel.

Abstract: Methods, devices, systems and compositions for detecting nucleic acids in polymerase chain reaction assays, such as droplet digital polymerase chain reaction (ddPCR) assays, using intercalating dyes. A dual surfactant system with at least one fluorosurfactant and at least one non-ionic non-fluorosurfactant may be employed for droplet generation and nucleic acid detection.

Abstract: System, including methods and compositions, for making and using emulsions that include a silicone oil and a silicone surfactant. The emulsions may include aqueous droplets disposed in a continuous phase that includes a silicone oil and a silicone surfactant. The aqueous droplets may contain an analyte, optionally at partial occupancy, and/or a luminescent (e.g., photoluminescent) reporter. An assay of the analyte may be performed with the droplets. In some cases, signals may be detected from the droplets, and a characteristic of the analyte, such as an analyte level or activity, may be determined based on the signals.

Abstract: The present disclosure provides methods, devices, systems and compositions for detecting nucleic acids in polymerase chain reaction assays, such as droplet digital polymerase chain reaction (ddPCR) assays. The present disclosure provides methods, devices, systems and compositions for detecting nucleic acids in ddPCR assays using intercalating dyes. A dual surfactant system with at least one fluorosurfactant and at least one non-ionic non-fluorosurfactant may be employed for droplet generation and nucleic acid detection.

Abstract: System, including methods, apparatus, and kits, for forming emulsions. In an exemplary method of generating droplets, a device may be selected that includes a plurality of emulsion-formation units each including a sample well, a continuous-phase well, a droplet well, and a channel network that fluidically interconnects the wells and creates a droplet-generation region. A discrete volume of sample-containing fluid may be placed into the sample well of each emulsion-formation unit, and a discrete volume of continuous-phase fluid into the continuous-phase well of each emulsion-formation unit. Pressure may be applied to the device with a fluidics assembly after the step of placing, such that the plurality of emulsion-formation units generate droplets in parallel with one another. A pressure signal may be detected from the fluidics assembly. Application of the pressure may be stopped when the pressure signal indicates that a sample well is empty.

Abstract: System, including methods and compositions, for making and using emulsions that include a silicone oil and a silicone surfactant. The emulsions may include aqueous droplets disposed in a continuous phase that includes a silicone oil and a silicone surfactant. The aqueous droplets may contain an analyte, optionally at partial occupancy, and/or a luminescent (e.g., photoluminescent) reporter. An assay of the analyte may be performed with the droplets. In some cases, signals may be detected from the droplets, and a characteristic of the analyte, such as an analyte level or activity, may be determined based on the signals.

Abstract: Method of detecting a signal from droplets for instrument calibration. In the method, a calibration standard for a droplet detection instrument may be received. The calibration standard may have been shipped at least one kilometer when received. The calibration standard may include a mixture of first droplets and second droplets. Each of the first and second droplets may be encapsulated by an immiscible carrier liquid and may have a stabilizing droplet skin that is formed by heating and that includes a skin-forming protein. Each the first droplets may contain a fluorescent dye, and each of the second droplets may contain a fluorescent dye. A fluorescence signal may be detected from a plurality of the first and second droplets with a droplet detection instrument. The fluorescence signal may be stronger for the first droplets than the second droplets.

Abstract: System, including methods, apparatus, and kits, for forming emulsions. In an exemplary method of generating droplets, a device may be selected that includes a plurality of emulsion-formation units each including a sample well, a continuous-phase well, a droplet well, and a channel network that fluidically interconnects the wells and creates a droplet-generation region. A discrete volume of sample-containing fluid may be placed into the sample well of each emulsion-formation unit, and a discrete volume of continuous-phase fluid into the continuous-phase well of each emulsion-formation unit. Pressure may be applied to the device with a fluidics assembly after the step of placing, such that the plurality of emulsion-formation units generate droplets in parallel with one another. A pressure signal may be detected from the fluidics assembly. Application of the pressure may be stopped when the pressure signal indicates that a sample well is empty.

Abstract: System, including methods, apparatus, and kits, for forming and concentrating emulsions. An exemplary system may comprise a device including a sample well configured to receive sample-containing fluid, a continuous-phase well configured to receive continuous-phase fluid, a droplet well, and a channel network interconnecting the wells. The system also may comprise an instrument configured to operatively receive the device and to create (i) a first pressure differential to produce an emulsion collected in the droplet well and (ii) a second pressure differential to decrease a volume fraction of continuous-phase fluid in the emulsion, after the emulsion has been collected in the droplet well, by selectively driving continuous-phase fluid, relative to sample-containing droplets, from the droplet well.

Abstract: System, including methods, apparatus, and kits, for forming and concentrating emulsions. An exemplary system may comprise a device including a sample well configured to receive sample-containing fluid, a continuous-phase well configured to receive continuous-phase fluid, a droplet well, and a channel network interconnecting the wells. The system also may comprise an instrument configured to operatively receive the device and to create (i) a first pressure differential to produce an emulsion collected in the droplet well and (ii) a second pressure differential to decrease a volume fraction of continuous-phase fluid in the emulsion, after the emulsion has been collected in the droplet well, by selectively driving continuous-phase fluid, relative to sample-containing droplets, from the droplet well.

Abstract: System, including methods, apparatus, and kits, for forming emulsions. An exemplary system may comprise a device including a sample well configured to receive sample-containing fluid, a continuous-phase well configured to receive continuous-phase fluid, and a droplet well. The device also may include a channel network having a first channel, a second channel, and a third channel that meet one another in a droplet-generation region. The system also may comprise a holder for the device. The system further may comprise an instrument configured to operatively receive an assembly including the device and the holder and to drive sample-containing fluid from the sample well to the droplet-generation region via the first channel, continuous-phase fluid from the continuous-phase well to the droplet-generation region via the second channel, and sample-containing droplets from the droplet-generation region to the droplet well via the third channel.

Abstract: Provided herein, are droplet mixture compositions and systems and methods for forming mixtures of droplets. The system may comprise two or more droplet generation units. Each unit may include at least one first input well, a second input well, and an output well connected to the first and second input wells by channels that form a droplet generator. The combined droplet populations can be mixed, heated, and collected for multiple uses, such as for use as calibration standards for instrument testing and analysis.

Abstract: This disclosure provides systems, devices, and methods for sample preparation and/or analysis comprising a droplet generator having a first channel in fluid communication with a carrier fluid reservoir and a second channel in fluid communication with a sample reservoir. The first channel and second channel may meet at an intersection that receives a sample from the sample reservoir and a carrier fluid from the carrier fluid reservoir and generates one or more droplets that flow along a droplet channel to a droplet reservoir. An energy application member in thermal communication with the intersection, at least a portion of the droplet channel, the sample reservoir and/or the carrier fluid reservoir may provide energy to an individual droplet of the one or more droplets, such as at the intersection and/or as the droplet moves along the droplet channel to the droplet reservoir.