Various aspects of the present invention relate to the control and manipulation of fluidic species, for example, in microfluidic systems. In one aspect, the invention relates to systems and methods for making droplets of fluid surrounded by a liquid, using, for example, electric fields, mechanical alterations, the addition of an intervening fluid, etc. In another aspect, the invention relates to systems and methods for dividing a fluidic droplet into two droplets, for example, through charge and/or dipole interactions with an electric field. The invention also relates to systems and methods for fusing droplets, according to another aspect of the invention, for example, through charge and/or dipole interactions. Another aspect of the invention provides the ability to determine droplets, or a component thereof, for example, using fluorescence and/or other optical techniques (e.g., microscopy), or electric sensing techniques such as dielectric sensing.

A flow cytometry apparatus includes a flow cytometer having a suction or negative-pressure intake probe, a support for a microplate having a plurality of sample wells, and motive elements operatively connected to at least one of the probe and the support for moving the intake probe and the support relative to one another so that the intake probe is sequentially aligned with different sample wells of the microplate. The apparatus has no fluid pumping elements between the support and the flow cytometer so that a bubble-separated sample stream is forced to the flow cytometer solely by virtue of a negative pressure communicated via the intake probe.

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 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.

A fluid handling and delivery system useful in generating a fluid stream in the flow path of microfluidic device.

A system for processing a biological sample includes a substrate comprising a plurality of wells and a plurality of flow channels. The system further includes a flow control system comprising a manifold having a plurality of ports configured to fluidically couple to the plurality of wells, and one or more containment structures configured to contain carrier fluid and fluidically couple to the ports. The flow control system further includes a cradle configured to removably receive the substrate. The flow control system is configured to transmit pressure differential, via the manifold, to the plurality of wells so as to cause a plurality of sample volumes held by at least some wells of the plurality of wells to flow through respective flow channels and cause the carrier fluid to flow through the flow channels and form a plurality of droplets of the plurality of sample volumes separated by the carrier fluid.

A system for processing a biological sample can include a droplet generation assembly comprising a plurality of first reservoirs configured to contain an aqueous sample and a plurality of second reservoirs configured to contain a carrier fluid immiscible with the aqueous sample. The plurality of first reservoirs and the plurality of second reservoirs can be arranged to be in respective flow communication in pairs of reservoirs comprising a first reservoir of the plurality of first reservoirs and a second reservoir of the plurality of second reservoirs constituting a plurality of pairs of reservoirs. The droplet generation assembly can further include a flow control system configured to control a pressure in the plurality of pairs of reservoirs so as to generate a flow of a series of volumes of the aqueous sample separated by the carrier fluid. The system can further include a thermocycling system.

Various aspects of the present invention relate to the control and manipulation of fluidic species, for example, in microfluidic systems. In one aspect, the invention relates to systems and methods for making droplets of fluid surrounded by a liquid, using, for example, electric fields, mechanical alterations, the addition of an intervening fluid, etc. In some cases, the droplets may each have a substantially uniform number of entities therein. For example, 95% or more of the droplets may each contain the same number of entities of a particular species. In another aspect, the invention relates to systems and methods for dividing a fluidic droplet into two droplets, for example, through charge and/or dipole interactions with an electric field. The invention also relates to systems and methods for fusing droplets according to another aspect of the invention, for example, through charge and/or dipole interactions. In some cases, the fusion of the droplets may initiate or determine a reaction. In a related aspect of the invention, systems and methods for allowing fluid mixing within droplets to occur are also provided. In still another aspect, the invention relates to systems and methods for sorting droplets, e.g., by causing droplets to move to certain regions within a fluidic system. Examples include using electrical interactions (e.g., charges, dipoles, etc.) or mechanical systems (e.g., fluid displacement) to sort the droplets. In some cases, the fluidic droplets can be sorted at relatively high rates, e.g., at about 10 droplets per second or more. Another aspect of the invention provides the ability to determine droplets, or a component thereof, for example, using fluorescence and/or other optical techniques (e.g., microscopy), or electric sensing techniques such as dielectric sensing.

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 relates to a system and method for moving samples, such as fluid, within a microfluidic system using a plurality of gas actuators for applying pressure at different locations within the microfluidic. The system includes a substrate which forms a fluid network through which fluid flows, and a plurality of gas actuators integral with the substrate. One such gas actuator is coupled to the network at a first location for providing gas pressure to move a microfluidic sample within the network. Another gas actuator is coupled to the network at a second location for providing gas pressure to further move at least a portion of the microfluidic sample within the network. A valve is coupled to the microfluidic network so that, when the valve is closed, it substantially isolates the second gas actuator from the first gas actuator.