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: Systems and methods for detection of a signal from droplets of an emulsion. An exemplary system may comprise a fluid transporter having a tube with an open end for aspirating droplets, a singulator to arrange the droplets in single file and to space the single-file droplets from one another, and a detection channel in optical communication with a detector configured to detect a signal from droplets. In some embodiments, the singulator may have a channel junction at which a stream of droplets in single file is combined with a stream of spacing fluid, and a tapered spacing channel extending downstream from the channel junction toward the detection channel. In some embodiments, the fluid transporter may suck droplet-containing fluid and spacing fluid through the detection channel from respective sources. In some embodiments, droplets may be subjected to a disaggregation routine before they are passed through the detection channel.

Abstract: Systems and methods for detection of a signal from droplets of an emulsion. An exemplary system may comprise a fluid transporter having a tube with an open end for aspirating droplets, a singulator to arrange the droplets in single file and to space the single-file droplets from one another, and a detection channel in optical communication with a detector configured to detect a signal from droplets. In some embodiments, the singulator may have a channel junction at which a stream of droplets in single file is combined with a stream of spacing fluid, and a tapered spacing channel extending downstream from the channel junction toward the detection channel. In some embodiments, the fluid transporter may suck droplet-containing fluid and spacing fluid through the detection channel from respective sources. In some embodiments, droplets may be subjected to a disaggregation routine before they are passed through the detection channel.

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: Microfluidic system, including methods and apparatus, for processing fluid, such as by droplet generation. In an exemplary method, a sample-containing fluid may be dispensed into a well through a sample port of a channel component. The channel component may include (a) a body having a bottom surface attached to the well, and a top surface with a microchannel formed therein, and (b) an input tube projecting into the well from the bottom surface of the body. The sample-containing fluid when dispensed may contact a bottom end of the input tube and may be retained, with assistance from gravity, out of contact with the microchannel. A pressure differential may be created that drives at least a portion of the sample-containing fluid from the well via the input tube and through the microchannel.

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: Systems and methods for detection of a signal from droplets of an emulsion. An exemplary system may comprise a fluid transporter having a tube with an open end for aspirating droplets, a singulator to arrange the droplets in single file and to space the single-file droplets from one another, and a detection channel in optical communication with a detector configured to detect a signal from droplets. In some embodiments, the singulator may have a channel junction at which a stream of droplets in single file is combined with a stream of spacing fluid, and a tapered spacing channel extending downstream from the channel junction toward the detection channel. In some embodiments, the fluid transporter may suck droplet-containing fluid and spacing fluid through the detection channel from respective sources. In some embodiments, droplets may be subjected to a disaggregation routine before they are passed through the detection channel.

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: Microfluidic system, including methods and apparatus, for processing fluid, such as by droplet generation. In an exemplary method, a sample-containing fluid may be dispensed into a well through a sample port of a channel component. The channel component may include (a) a body having a bottom surface attached to the well, and a top surface with a microchannel formed therein, and (b) an input tube projecting into the well from the bottom surface of the body. The sample-containing fluid when dispensed may contact a bottom end of the input tube and may be retained, with assistance from gravity, out of contact with the microchannel. A pressure differential may be created that drives at least a portion of the sample-containing fluid from the well via the input tube and through the microchannel.

Abstract: Microfluidic system, including methods and apparatus, for processing fluid, such as by droplet generation. In an exemplary method, a sample-containing fluid may be dispensed into a well through a sample port of a channel component. The channel component may include (a) a body having a bottom surface attached to the well, and a top surface with a microchannel formed therein, and (b) an input tube projecting into the well from the bottom surface of the body. The sample-containing fluid when dispensed may contact a bottom end of the input tube and may be retained, with assistance from gravity, out of contact with the microchannel. A pressure differential may be created that drives at least a portion of the sample-containing fluid from the well via the input tube and through the microchannel.

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: Methods of generating droplets. In an exemplary method, a device including a sample well, a carrier well, a droplet well, and a plurality of microfluidic channels is selected. The microfluidic channels include a first channel, a second channel, and a third channel. A discrete volume of sample-containing fluid is placed into the sample well, and a discrete volume of carrier fluid is placed into the carrier well. A pressure differential is created after placing the discrete volumes, to cause fluid flow. Sample-containing fluid flows from the sample well to a droplet-generation region of the device via the first channel. Carrier fluid flows from the carrier well to the droplet-generation region via the second channel. Sample-containing droplets and carrier fluid flow from the droplet-generation region to the droplet well via the third channel.

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: Microfluidic system, including methods and apparatus, for processing fluid, such as by droplet generation. In an exemplary method, a sample-containing fluid may be dispensed into a well through a sample port of a channel component. The channel component may include (a) a body having a bottom surface attached to the well, and a top surface with a microchannel formed therein, and (b) an input tube projecting into the well from the bottom surface of the body. The sample-containing fluid when dispensed may contact a bottom end of the input tube and may be retained, with assistance from gravity, out of contact with the microchannel. A pressure differential may be created that drives at least a portion of the sample-containing fluid from the well via the input tube and through the microchannel.

Abstract: Method of detection for droplet-based assays. In an exemplary method, an open end of a channel network may be placed into an emulsion. Droplets of the emulsion may be driven along a flow path from the open end, through a confluence region where a dilution fluid is introduced into the flow path from at least one dilution inlet channel to increase an average distance between droplets, and through an examination region disposed downstream of the confluence region. Light may be detected from the examination region as droplets pass through. The channel network may include a droplet inlet channel that meets the at least one dilution inlet channel at the confluence region. The droplet inlet channel may form a tapered region that is sized such that droplets leave the tapered region in single file.

Abstract: Oil compositions and methods for use in droplet formation or in spacing of droplets are disclosed. The oil compositions may include a combination, such as a silicone oil and a fluorine-containing compound. The droplets can contain analytes (e.g., nucleic acids) and may be used for molecular reactions (e.g., digital PCR) and detection.

Abstract: Microfluidic system, including methods and apparatus, for processing fluid, such as by droplet generation. In some embodiments, the system may include a well and a channel component attached to the well. The channel component may include (a) a body, (b) an input tube (a “fluid pickup”) projecting from a bottom surface of the body and having an open bottom end disposed in the input well, (c) a microchannel, and (d) a passage extending through the input tube and the body and connecting the well to the microchannel. The system may be configured to receive a sample-containing fluid in the well and retain the sample-containing fluid below a top end of the passage, until a pressure differential is created that drives at least a portion of the sample-containing fluid from the well via the passage and through the microchannel.

Abstract: Method of transporting droplets for detection. An emulsion disposed in a container and including droplets may be provided. Contact may be created between a tip and the emulsion. The tip may be connected to an examination region and may include an outer tube and an inner tube. The outer tube may form a first open end and surround an enclosed portion of the inner tube. The inner tube may extend out of the first open end to create a projecting portion forming a second open end below the first open end. Droplets of the emulsion may be loaded into the inner tube via the second open end. Loaded droplets may be moved from the inner tube to the examination region. Fluid may be dispensed onto the projecting portion of the inner tube from the first open end formed by the outer tube.

Abstract: System, including methods and apparatus, for detection of spaced droplets.