Abstract: This invention generally relates to systems and methods for the formation and/or control of fluidic species, and articles produced by such systems and methods. In some cases, the invention involves unique fluid channels, systems, controls, and/or restrictions, and combinations thereof. In certain embodiments, the invention allows fluidic streams (which can be continuous or discontinuous, i.e., droplets) to be formed and/or combined, at a variety of scales, including microfluidic scales. In one set of embodiments, a fluidic stream may be produced from a channel, where a cross-sectional dimension of the fluidic stream is smaller than that of the channel, for example, through the use of structural elements, other fluids, and/or applied external fields, etc. In some cases, a Taylor cone may be produced.

Abstract: Microfluidic structures and methods for manipulating fluids, fluid components, and reactions are provided. In one aspect, such structures and methods can allow production of droplets of a precise volume, which can be stored/maintained at precise regions of the device. In another aspect, microfluidic structures and methods described herein are designed for containing and positioning components in an arrangement such that the components can be manipulated and then tracked even after manipulation. For example, cells may be constrained in an arrangement in microfluidic structures described herein to facilitate tracking during their growth and/or after they multiply.

Abstract: The present invention generally relates to microfluidics and labeled nucleic acids. Certain aspects are generally directed to containing cells in gels, such as agarose gels, and determining nucleic acids within the cells, e.g., while contained within the gels. The nucleic acids may be, for example, genomic DNA, mRNA, transcriptomes, or the like. In some embodiments, for instance, both genomic DNA and RNA (e.g., as in a transcriptome) from a cell may be determined. In some cases, the nucleic acids may be attached to beads for sequencing or other purposes. Such systems may be useful, for example, for high-throughput sequencing or other applications.

Abstract: The present invention generally relates to a combination of molecular barcoding and emulsion-based microfluidics to isolate, lyse, barcode, and prepare nucleic acids from individual cells in a high-throughput manner.

Abstract: The present invention generally relates to microfluidic devices. In some aspects, various entities, such as droplets or particles, may be contained within a microfluidic device, e.g., within collection chambers or other locations within the device. In some cases, the entities may be released from such locations, e.g., in a sequential pattern, or an arbitrary pattern. In some cases, the entities may be imaged, reacted, analyzed, etc. while contained within the collection chambers. Other aspects are generally directed to methods of making or using such devices, kits involving such devices, or the like.

Abstract: The present invention generally relates to the manipulation of fluids using acoustic waves such as surface acoustic waves. In some aspects, one fluid may be introduced into another fluid via application of suitable acoustic waves. For example, a fluid may be added or injected into another fluid by applying acoustic waves where, in the absence of the acoustic waves, the fluid cannot be added or injected, e.g., due to the interface or surface tension between the fluids. Thus, for example, a fluid may be injected into a droplet of another fluid. Other embodiments of the invention are generally directed to systems and methods for making or using such systems, kits involving such systems, or the like.

Abstract: This invention generally relates to systems and methods for the formation and/or control of fluidic species, and articles produced by such systems and methods. In some cases, the invention involves unique fluid channels, systems, controls, and/or restrictions, and combinations thereof. In certain embodiments, the invention allows fluidic streams (which can be continuous or discontinuous, i.e., droplets) to be formed and/or combined, at a variety of scales, including microfluidic scales. In one set of embodiments, a fluidic stream may be produced from a channel, where a cross-sectional dimension of the fluidic stream is smaller than that of the channel, for example, through the use of structural elements, other fluids, and/or applied external fields, etc. In some cases, a Taylor cone may be produced.

Abstract: The present invention generally relates to fluidic droplets and systems and methods for determining immune or other cells. Some aspects of the invention are generally directed to assays that combine sensitive detection of secreted products with detection of target cell death in droplets containing an effector cell, systems and methods to isolate droplets in which one or more cell interactions have occurred, or systems and methods to generate nucleic acid information from cell interactions. In addition, some embodiments of the invention are generally directed to containing two (or more) cells in droplets, e.g., an effector cell and one or more target cells, and determining various interactions between the cells within the droplets, such as whether the effector cell kills the target cell, whether the effector cell releases antibodies, cytokines or other substances that are able to interact with the target cell or are released in the presence of the target cell, or the like.

Abstract: The present invention generally relates to the production of fluidic droplets. Certain aspects of the invention are generally directed to systems and methods for creating droplets by flowing a fluid from a first channel to a second channel through a plurality of side channels. The fluid exiting the side channels into the second channel may form a plurality of droplets, and in some embodiments, at very high droplet production rates. In addition, in some aspects, double or higher-order multiple emulsions may also be formed. In some embodiments, this may be achieved by forming multiple emulsions through a direct, synchronized production method and/or through the formation of a single emulsion that is collected and re-injected into a second microfluidic device to form double emulsions.

Abstract: The present invention generally relates to droplets and/or emulsions, such as multiple emulsions. In some cases, the droplets and/or emulsions may be used in assays, and in certain embodiments, the droplet or emulsion may be hardened to form a gel. In some aspects, a heterogeneous assay can be performed using a gel. For example, a droplet may be hardened to form a gel, where the droplet contains a cell, DNA, or other suitable species. The gel may be exposed to a reactant, and the reactant may interact with the gel and/or with the cell, DNA, etc., in some fashion. For example, the reactant may diffuse through the gel, or the hardened particle may liquefy to form a liquid state, allowing the reactant to interact with the cell. As a specific example, DNA contained within a gel particle may be subjected to PCR (polymerase chain reaction) amplification, e.g., by using PCR primers able to bind to the gel as it forms. As the DNA is amplified using PCR, some of the DNA will be bound to the gel via the PCR primer.

Abstract: Microfluidic structures and methods for manipulating fluids, fluid components, and reactions are provided. In one aspect, such structures and methods can allow production of droplets of a precise volume, which can be stored/maintained at precise regions of the device. In another aspect, microfluidic structures and methods described herein are designed for containing and positioning components in an arrangement such that the components can be manipulated and then tracked even after manipulation. For example, cells may be constrained in an arrangement in microfluidic structures described herein to facilitate tracking during their growth and/or after they multiply.

Abstract: 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.

Abstract: The invention describes a method for the synthesis of compounds comprising the steps of: (a) compartmentalizing two or more sets of primary compounds into microcapsules; such that a proportion of the microcapsules contains two or more compounds; and (b) forming secondary compounds in the microcapsules by chemical reaction between primary compounds from different sets; wherein one or both of steps (a) and (b) is performed under microfluidic control; preferably electronic microfluidic control. The invention further allows for the identification of compounds which bind to a target component of a biochemical system or modulate the activity of the target, and which is co-compartmentalized into the microcapsules.

Abstract: The present invention generally relates to the production of fluidic droplets. Certain aspects of the invention are generally directed to systems and methods for creating droplets by flowing a fluid from a first channel to a second channel through a plurality of side channels. The fluid exiting the side channels into the second channel may form a plurality of droplets, and in some embodiments, at very high droplet production rates. In addition, in some aspects, double or higher-order multiple emulsions may also be formed. In some embodiments, this may be achieved by forming multiple emulsions through a direct, synchronized production method and/or through the formation of a single emulsion that is collected and re-injected into a second microfluidic device to form double emulsions.

Abstract: The present invention generally relates to a controlled fluidic device to develop spatially complex environments to enhance the rate of evolution in cell populations. The method further provides an enhanced understanding in the emergence, for example, drug resistance during cancer chemotherapy.

Abstract: The present invention generally relates to microfluidics and labeled nucleic acids. For example, certain aspects are generally directed to systems and methods for labeling nucleic acids within microfluidic droplets. In one set of embodiments, the nucleic acids may include “barcodes” or unique sequences that can be used to distinguish nucleic acids in a droplet from those in another droplet, for instance, even after the nucleic acids are pooled together. In some cases, the unique sequences may be incorporated into individual droplets using particles and attached to nucleic acids contained within the droplets (for example, released from lysed cells). In some cases, the barcodes may be used to distinguish tens, hundreds, or even thousands of nucleic acids, e.g., arising from different cells or other sources.

Abstract: The present invention generally relates to microfluidic droplets and, in particular, to multiple emulsion microfluidic droplets. In certain aspects, particles such as gel particles can be prepared in an aqueous carrier from aqueous droplets (or a non-aqueous carrier from non-aqueous droplets). For example, in some embodiments, double-emulsion droplets of a first fluid, surrounded by a second fluid, contained in a carrier fluid may be prepared, where the first fluid forms a gel and the second fluid is removed. For instance, the second fluid may be dissolved in the carrier fluid, or the second fluid may be hardened, then removed, for example, due to a change in pH. Other embodiments of the present invention are generally directed to kits containing such microfluidic droplets, microfluidic devices for making such microfluidic droplets, or the like.

Abstract: The invention describes a method for isolating one or more genetic elements encoding a gene product having a desired activity, comprising the steps of: (a) compartmentalising genetic elements into microcapsules; and (b) sorting the genetic elements which express the gene product having the desired activity; wherein at least one step is under microfluidic control. The invention enables the in vitro evolution of nucleic acids and proteins by repeated mutagenesis and iterative applications of the method of the invention.

Abstract: The invention describes a method for the synthesis of compounds comprising the steps of: (a) compartmentalising two or more sets of primary compounds into microcapsules; such that a proportion of the microcapsules contains two or more compounds; and (b) forming secondary compounds in the microcapsules by chemical reactions between primary compounds from different sets; wherein one or both of steps (a) and (b) is performed under microfluidic control; preferably electronic microfluidic control The invention further allows for the identification of compounds which bind to a target component of a biochemical system or modulate the activity of the target, and which is co-compartmentalised into the microcapsules.

Abstract: The present invention generally relates to microfluidics and/or epigenetic sequencing. In one set of embodiments, cells contained within a plurality of microfluidic droplets are lysed and the DNA (e.g., from nucleosomes) within the droplets are labeled, e.g., with adapters containing an identification sequence. The adapters may also contain other sequences, e.g., restriction sites, primer sites, etc., to assist with later analysis. After labeling with adapters, the DNA from the different cells may be combined and analyzed, e.g., to determine epigenetic information about the cells. For example, the DNA may be separated on the basis of certain modifications (e.g., methylation), and the DNA from the separated nucleosomes may be sequenced using techniques such as chromatin immunoprecipitation (“ChIP”). In some cases, the DNA sequences may also be aligned with genomes, e.g., to determine which portions of the genome were epigenetically modified, e.g., via methylation.