This invention relates generally to devices, systems, and methods for performing biological assays by using indicators that modify one or more optical properties of the assayed biological samples. The subject methods include generating a reaction product by carrying out a biochemical reaction on the biological sample introduced into a device and reacting the reaction product with an indicator capable of generating a detectable change in an optical property of the biological sample to indicate the presence, absence, or amount of analyte suspected to be present in the sample.

There are provided methods, and devices for assaying for a binding interaction between a protein, such as a monoclonal antibody, produced by a cell, and a biomolecule. The method may include retaining the cell within a chamber having an aperture; exposing the protein produced by the cell to a capture substrate, wherein the capture substrate is in fluid communication with the protein produced by the cell and wherein the capture substrate is operable to bind the protein produced by the cell; flowing a fluid volume comprising the biomolecule through the chamber via said aperture, wherein the fluid volume is in fluid communication with the capture substrate; and determining a binding interaction between the protein produced by the cell and the biomolecule.

The present description provides, in some embodiments, an apparatus for mixing a fluid in a circuit having an inlet channel defining a flow path for a fluid including particulate matter, a first reagent channel in fluid communication with the inlet channel and defining a first reagent flow path for a first reagent, the inlet channel and first reagent channel configured to shear the fluid entering the first reagent channel from the inlet channel at a first junction, a shearing channel in fluid communication with the inlet channel and first reagent channel at the first junction, and a diffusion channel in fluid communication with the shearing channel at a second junction, the sheared fluid collectable into the diffusion channel such that the fluid is compressed at least in part by the first reagent to have a thickness close to a diameter of the particulate matter in the fluid.

Methods and devices for detecting metabolic activity of target cells in a sample. The target cells are concentrated in a nanoliter well having a microfilter. A reporter compound that exhibits a change in electrochemical state in response to metabolic activity of the target cells is introduced. Metabolic activity or viability of the target cells is detected based on a determined change in the electrochemical state of contents in the well.

Selectively vented biological assay devices and methods of performing biological assays with such devices are provided herein. Disclosed devices include a selective venting element having passively tunable porosity. The methods include controlling fluid flow within the subject devices with the selective venting element.

A device is described having a first surface having a plurality of first areas and a second surface having a plurality of second areas. The first surface and the second surface are opposed to one another and can move relative to each other from at least a first position where none of the plurality of first areas, having a first substance, are exposed to plurality of second areas, having a second substance, to a second position. When in the second position, the plurality of first and second areas, and therefore the first and second substances, are exposed to one another. The device may further include a series of ducts in communication with a plurality of first second areas to allow for a substance to be disposed in, or upon, the plurality of second areas when in the first position.

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.

We describe a method comprising: providing a droplet comprising a plurality of constituents, splitting said droplet into a first droplet and a second droplet, wherein said first droplet comprises a first fraction of said plurality of constituents and said second droplet comprises a second fraction of said plurality of constituents, analysing said constituents of said first fraction of said plurality of constituents in said first droplet, and sorting said second droplet dependent on an outcome of said analysis.

Devices, systems, and methods for detecting molecules of interest within a collected sample are described herein. In certain embodiments, self-contained sample analysis systems are disclosed, which include a reusable reader component, a disposable cartridge component, and a disposable sample collection component. In some embodiments, the reader component communicates with a remote computing device for the digital transmission of test protocols and test results. In various disclosed embodiments, the systems, components, and methods are configured to identify the presence, absence, and/or quantity of particular nucleic acids, proteins, or other analytes of interest, for example, in order to test for the presence of one or more pathogens or contaminants in a sample.

Described herein are devices and methods for high throughput purification of particles. In some cases, methods and devices described herein can be used to remove erythrocytes and purify leukocytes and raise the quality of umbilical cord blood and other transplant grafts, thereby significantly improving patient outcomes.