The present invention generally relates to microfluidic droplets and, including forming gels within microfluidic droplets. In some aspects, a fluid containing agarose or other gel precursors is transported into a microfluidic droplet, and caused to harden within the droplet, e.g., to form a gel particle contained within the microfluidic droplet. Surprisingly, a discrete gel particle may be formed even if the fluid containing the agarose or other gel precursor, and the fluid contained within the microfluidic droplet, are substantially immiscible. Other aspects of the present invention are generally directed to techniques for making or using such gels within microfluidic droplets, kits containing such gels within microfluidic droplets, or the like.

Microfluidic pumps are provided that use electrowetting to manipulate the location of one or more droplets of a working fluid (e.g., water) in order to pump tears, blood, laboratory samples, carrier fluid, or some other payload fluid. The working fluid is separated from the payload fluid by one or more droplets of an isolating fluid that is immiscible with the working fluid. The working fluid is manipulated via electrowetting, by applying voltages to two or more electrodes, to repeatedly move back and forth. Forces, pressures, and/or fluid flows exerted by the working fluid are coupled to the payload fluid via the droplet(s) of isolation fluid and reed valves, diffuser nozzles, or other varieties of valve can act as flow-rectifying elements to convert the coupled forces into a net flow of the payload fluid through the pump.

The present disclosure provides a chip, a microfluidic device including the chip, and a method for sorting target droplets. The chip includes a first container for accommodating a first fluid, a second container for accommodating a second fluid, a delivery channel including a first flow channel communicating with the first container and a second flow channel communicating with the second container, the first flow channel and the second flow channel intersecting and communicating with each other at a junction, and at least one collector. A portion of the first flow channel includes the junction and is divided into two sections by the junction, in each section, the section thickens gradually along a first direction away from the junction. The second flow channel includes the junction and is divided into two sections by the junction, in each section, the section thickens gradually along a second direction away from the junction.

The present invention relates to systems and methods for the arrangement of droplets in pre-determined locations. Many applications require the collection of time-resolved data. Examples include the screening of cells based on their growth characteristics or the observation of enzymatic reactions. The present invention provides a tool and related techniques which addresses this need, and which can be used in many other situations. The invention provides, in one aspect, a tool that allows for stable storage and indexing of individual droplets. The invention can interface not only with microfluidic/microscale equipment, but with macroscopic equipment to allow for the easy injection of liquids and extraction of sample droplets, etc.

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.

Methods are provided for separating magnetically responsive beads from a droplet in a droplet actuator. Droplet operations electrodes and a magnet are arranged in a droplet actuator to manipulate a bead-containing droplet and position it relative to a magnetic field region that attracts the magnetically responsive beads. The droplet operations electrodes are operated to control the droplet shape and transport it away from the magnetic field region to form a concentration of beads in the droplet. The continued transport of the droplet away from the magnetic field causes the concentration of beads to break away from the droplet to yield a small, concentrated bead-containing droplet immobilized by the magnet.

Resolution of images used in processes such as sequencing by synthesis may be increased by structuring sites that would emit signals in the images to have different elevations. Differences in focus caused by these differences in elevation may be used to filter out background illumination, thereby providing an image in which in focus sites may be resolved even though the separation between any site and its nearest neighbor may be below the diffraction limit of the light that would be emitted.

Systems and methods for in-context editing of web pages in which the production format of a web page is visible while the web page is being edited, and the editable image is not distorted by the editing tools. In one embodiment, a system includes a server computer, a client computer and a transmission channel coupled between them. The server computer receives a request for a web page from the client computer and responsively transmits a web page containing in-context editing tools to the client computer. The client computer operate alternately in a first mode in which the in-context editing tools are superimposed on a web page image, or a second mode in which the web page image is displayed, but the in-context editing tools are hidden. The tools overlay in the first mode does not alter the production format of the web page image as displayed in the second mode.

A fluidic chip comprising: a sealing layer having an upper surface and a lower surface; and a formed part comprising a generally planar body having a lower surface sealed with the upper surface of the sealing layer, the generally planar body having a number of through holes and a number of wells in fluid communication with the number of through holes, wherein together with the upper surface of the sealing layer, the number of through holes and the number of wells respectively define a number of fluid inlets and a number of fluid chambers in fluid connection with each other in the fluidic chip.

Described herein are digital microfluidic (DMF) devices and corresponding methods for managing reagent solution evaporation during a reaction. Reactions on the DMF devices described here are performed in an air or gas matrix. The DMF devices include a means for performing reactions at different temperatures. To address the issue of evaporation of the reaction droplet especially when the reaction is performed at higher temperatures, a means for introducing a replenishing droplet has been incorporated into the DMF device. A replenishing droplet is introduced every time when it has been determined that the reaction droplet has fallen below a threshold volume. Detection and monitoring of the reaction droplet may be through visual, optical, fluorescence, colorimetric, and/or electrical means.