Abstract: Disclosed herein is a novel method of producing monodisperse aqueous droplets, as well as a novel microfluidic droplet generator. In some examples, the method comprises flowing an aqueous solution through a microchannel and into a sample reservoir of the microfluidic droplet generator, wherein monodisperse droplets of the aqueous solution form by step-emulsification at a step change in height at an intersection of a reservoir end of the microchannel and a sidewall of the sample reservoir. In some examples, the aqueous solution is a hydrogel precursor solution and monodisperse droplets of the hydrogel precursor solution form by step-emulsification at the step change in height at the intersection of the reservoir end of the microchannel and the sidewall of the sample reservoir. In some examples, the monodisperse droplets of the hydrogel precursor solution are incubated under conditions suitable for gelation to form hydrogel beads.

Abstract: An example of a flow cell includes a substrate, a plurality of chambers defined on or in the substrate, and a plurality of depressions defined in the substrate and within a perimeter of each of the plurality of chambers. The depressions are separated by interstitial regions. Primers are attached within each of the plurality of depressions, and a capture site is located within each of the plurality of chambers.

Abstract: An example of a sequencing kit includes a flow cell, an encapsulation matrix precursor composition, and a radical initiator. The flow cell includes a plurality of chambers and primers attached within each of the plurality of chambers. The encapsulation matrix precursor composition consists of a fluid, a monomer or polymer including a radical generating and chain elongating functional group, a radical source, and a crosslinker. The radical initiator is part of the encapsulation matrix precursor composition or is a separate component.

Abstract: An example of a flow cell includes a substrate, which includes nano-depressions defined in a surface of the substrate, and interstitial regions separating the nano-depressions. A hydrophobic material layer has a surface that is at least substantially co-planar with the interstitial regions and is positioned to define a hydrophobic barrier around respective sub-sets of the nano-depressions.

Abstract: Implementations of a method for seeding sequence libraries on a surface of a sequencing flow cell that allow for spatial segregation of the libraries on the surface are provided. The spatial segregation can be used to index sequence reads from individual sequencing libraries to increase efficiency of subsequent data analysis. In some examples, hydrogel beads containing encapsulated sequencing libraries are captured on a sequencing flow cell and degraded in the presence of a liquid diffusion barrier to allow for the spatial segregation and seeding of the sequencing libraries on the surface of the flow cell. Additionally, examples of systems, methods and compositions are provided relating to flow cell devices configured for nucleic acid library preparation and single cell sequencing. Some examples include flow cell devices having a hydrogel with genetic material disposed therein, and which is retained within the hydrogel during nucleic acid processing.

Abstract: Described are microfluidic devices and methods for providing a predetermined number of microspheres or beads, together with a cell, within a fluid droplet being processed. The system may provide each droplet with a single bead and a single cell, and the bead may contain DNA or other reagents for later identifying the specific cell associated with that bead.

Abstract: Systems, methods, and compositions provided herein relate to preparation of beads encapsulating long DNA fragments for high-throughput spatial indexing. Some embodiments include preparation of nucleic acid libraries within the bead, wherein the bead includes pores that allow diffusion of reagents while retaining genetic material.

Abstract: An apparatus for directing fluid into and out of a fluidic device includes two or more fluid prime channels connected to a fluid inlet of the fluidic device, a flow control valve for each fluid prime channel to control flow between the fluid prime channel and the fluid inlet, one or more outlet channels connected to a fluid outlet of the fluidic device, and a flow control valve for each outlet channel to control flow between the fluid outlet and the associated outlet channel. An apparatus for delivering fluids to a fluid inlet includes a plate that is rotatable about an axis of rotation and a plurality of fluid compartments disposed on the plate, each compartment having a fluid exit port disposed at a common radial distance from the axis of rotation and positioned to align with the fluid inlet as the plate rotates about the axis of rotation.

Abstract: Described are microfluidic devices and methods for providing a predetermined number of microspheres or beads, together with a cell, within a fluid droplet being processed. The system may provide each droplet with a single bead and a single cell, and the bead may contain DNA or other reagents for later identifying the specific cell associated with that bead.

Abstract: Analysis of samples is facilitated. According to an example embodiment, an electrophoresis approach involves electrophoretically stacking and/or separating a sample or samples. An electrolyte and a mixture of one or more samples with another electrolyte are added to a microchannel or capillary. An electric field is applied to stack (and, in some applications, further separate) the one or more samples. Generally, the electric field and electrolyte are used to facilitate isotachophoretic (ITP) stacking. In some embodiments, a further electric field is applied and used with the electrolyte to facilitate subsequent capillary electrophoresis (CE).