A microfabricated sheath flow structure for producing a sheath flow includes a primary sheath flow channel for conveying a sheath fluid, a sample inlet for injecting a sample into the sheath fluid in the primary sheath flow channel, a primary focusing region for focusing the sample within the sheath fluid and a secondary focusing region for providing additional focusing of the sample within the sheath fluid. The secondary focusing region may be formed by a flow channel intersecting the primary sheath flow channel to inject additional sheath fluid into the primary sheath flow channel from a selected direction. A sheath flow system may comprise a plurality of sheath flow structures operating in parallel on a microfluidic chip.

Methods and systems for sorting particles are provided. Methods and systems for sorting cell beads are provided. In some cases, cell beads may be sorted from particles unoccupied with cell derivatives. In some cases, singularly occupied cell beads may be sorted from unoccupied particles and multiply occupied cell beads.

The invention relates to a method for ordering, sorting and/or focusing particles in a first microfluidic channel system, the method comprising the steps of i) providing for a first microfluidic channel comprising at least a first and a second inlet and a first outlet, ii) injecting a first fluid into the channel through said first inlet, iii) injecting a second fluid into the channel through said second inlet, wherein the viscosity of the first fluid is higher than the viscosity of the second fluid, such that the two fluids flow in a laminar fashion unmixed side by side, and one of the two fluids comprises the particles to be ordered, sorted and/or focused. The invention also relates to a microfluidic channel system for sorting different particles into one droplet.

Parallel uses of microfluidic methods and devices for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid are described. In some aspects, the present invention relates generally to flow-focusing-type technology, and also to microfluidics, and more particularly parallel use of microfluidic systems arranged to control a dispersed phase within a dispersant, and the size, and size distribution, of a dispersed phase in a multi-phase fluid system, and systems for delivery of fluid components to multiple such devices.

Parallel uses of microfluidic methods and devices for focusing and/or forming discontinuous sections of similar or dissimilar size in a fluid are described. In some aspects, the present invention relates generally to flow-focusing-type technology, and also to microfluidics, and more particularly parallel use of microfluidic systems arranged to control a dispersed phase within a dispersant, and the size, and size distribution, of a dispersed phase in a multi-phase fluid system, and systems for delivery of fluid components to multiple such devices.

Multistage deterministic lateral displacement devices, methods of forming the devices, and methods of separating a fluid mixture including particles having three or more particle sizes generally include a first module and at least one additional module. Each module includes a condenser portion and a separate portion. The condenser portion is generally configured to focus a streamline of all particles to a center of a channel whereas the separator separates the streamline of all particles into two different streamlines. One of the streamlines focuses the largest particles in the fluid mixture along a sidewall of the channel and the other streamline of smaller particles is between opposing sidewalls that define the channel. Each additional module can be used to further separate the largest particles remaining in the fluid mixture from the smaller particles.

The present invention relates to systems and methods for manipulating droplets within a high through put microfluidic system.

Method of analysis. In the method, a microfluidic device defining a flow path extending from an inlet to an outlet may be selected. A sample-containing fluid may be introduced into the flow path via the inlet. Volumes of the sample-containing fluid may be isolated from one another on the flow path. A two-dimensional monolayer of the volumes may be imaged. The two-dimensional monolayer may be formed along the flow path between the inlet and the outlet.

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.

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. After the PCR reaction, unbound DNA may be removed from the gel, e.g., via diffusion or washing. Thus, a gel particle having bound DNA may be formed in one embodiment of the invention.