In a method for mixing two liquid components of a medium with the aid of a static mixer, the two components are supplied to the static mixer, are mixed therein and are subsequently dispensed from the mixer. In this respect, only one respective component is supplied to the mixer, while the other component is not supplied to the mixer.

Multiple emulsions and techniques for the formation of multiple emulsions are generally described. A multiple emulsion, as used herein, describes larger droplets that contain one or more smaller droplets therein. In some embodiments, the larger droplet or droplets may be suspended in a carrying fluid containing the larger droplets that, in turn, contain the smaller droplets. As described below, multiple emulsions can be formed in one step in certain embodiments, with generally precise repeatability, and can be tailored in some embodiments to include a relatively thin layer of fluid separating two other fluids.

The invention generally relates to methods for forming mixed droplets. In certain embodiments, methods of the invention involve forming a droplet, and contacting the droplet with a fluid stream, wherein a portion of the fluid stream integrates with the droplet to form a mixed droplet.

Apparatus and methods for dispensing small beads of a viscous, mixed fluid material formed by first and second viscous fluids. The apparatus includes first and second metering rods for moving in a reciprocating manner, such that the first metering rod extends into a first fluid passageway, and the second metering rod extends into a second fluid passageway. A mixing passage communicates with the first and second fluid passageways to receive the first and second viscous fluids from the first and second fluid passageways. A dispensing passageway is in fluid communication with the mixing passage, and dispenses a small bead of viscous, mixed fluid material formed by the mixed first and second viscous fluids. A control retracts the first and second metering rods to prevent drooling of the viscous, mixed fluid material from the dispensing passageway after a dispensing cycle.

The present disclosure provides methods and compositions for detecting polynucleotides in a sample and for quantifying polynucleotide load in a sample. The polynucleotides can be associated with a disease, disorder, or condition. In some applications, methylated DNA is quantified, e.g., in order to determine the load of polynucleotides in a sample. The present disclosure also provides methods and compositions for determining the load of fetal polynucleotides in a biological sample, e.g., the load of fetal polynucleotides (e.g., DNA, RNA) in maternal plasma. The present disclosure provides methods and compositions for detecting cellular processes such as cellular viability, growth rates, and infection rates. This disclosure also provides compositions and methods for detecting differences in copy number of a target polynucleotide. In some embodiments, the methods and compositions provided herein are useful for diagnosis of fetal genetic abnormalities, when the starting sample is maternal tissue (e.g., blood, plasma). The methods and materials described apply techniques for allowing detection of small, but statistically significant, differences in polynucleotide copy number.

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.

A microchannel device includes: an upstream channel portion configured to allow an upstream liquid plug and a gas to flow therethrough; a downstream channel portion configured to allow a downstream liquid plug and a gas to flow therethrough; a liquid holding portion provided between a downstream end portion of the upstream channel portion and an upstream end portion of the downstream channel portion, the liquid holding portion being configured to hold a main liquid plug therein; and a gas bypass channel portion provided so as to bypass the liquid holding portion from the downstream end portion of the upstream channel portion to the upstream end portion of the downstream channel portion, the gas bypass channel portion being configured to allow the gas to flow therethrough in a state in which the liquid holding portion holds the main liquid plug.

The present invention generally relates to colloids and methods for changing the arrangement of droplet phases. In some embodiments, the colloids and methods comprise a plurality of droplets comprising two or more components, such that the two or more components can change arrangement of the components in the presence of an external stimulus. In some embodiments, the change in component arrangement is reversible. In certain embodiments, the change in component arrangement forms Janus droplets.

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.

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.