The present invention provides methods and apparatus for manipulating and interrogating the contents of large numbers of microdroplets in parallel on a surface of a microfluidic chip. According to one aspect of the invention a method is provided for manipulating and inspecting microdroplets on a microfluidic chip by optically- mediated electrowetting (oEWOD), the method comprising forming, using a first optical assembly, a plurality of oEWOD traps on a surface of the chip and forming, using a second optical assembly, a second array of oEWOD traps on the surface of the chip, and making an adjustment to the first optical assembly whilst one or more of the microdroplets are held in place by second array of oEWOD traps. Apparatus comprising a microfluidic chip and first and second optical assemblies is also provided.

Disclosed are microfluidic flow-based electroporation systems that have a flow device, an electrical control module, a fluid delivery module, and a multi-well module. The systems can be used in methods of selecting an electroporation parameter, and in methods of electroporating cells using the selected parameters.

An object separator may include a substrate, a fluid channel supported by the substrate, a pair of electrodes along the fluid channel to form a dielectrophoretic force to interact with an object entrained in a fluid, and an inertial pump supported by the substrate and positioned within the fluid channel to move the fluid along the fluid channel.

Methods and systems for capture object-based assays, including for determining a measure of the concentration of an analyte molecule or particle in a fluid sample, are described. The methods and systems may relate to high sensitivity detection of analytes, sometimes using assay conditions and sample handling that result in the capture and detection of a high percentage of the analyte molecules or particles in a fluid sample using relatively few capture objects. Apparatuses and methods for immobilizing capture objects with respect to assay sites, in some instances with unexpectedly high efficiencies are also described. Some such apparatuses involve the use of force fields and fluid meniscus forces, alone or in combination, to facilitate or improve capture object immobilization. Also described are techniques for utilizing a relatively high percentage of capture objects in an assay sample, such as by using disclosed sample washing techniques, imaging systems, and analysis procedures that can reduce capture object loss.

A microfluidic device is provided. In one aspect, the microfluidic device includes a microfluidic channel, and a first actuator including an array of electrodes along the microfluidic channel. The first actuator is configured to generate a a potential wave along the microfluidic channel. Each electrode of the array can see its voltage changing cyclically according to a period multiplied by a natural number, wherein for at least one electrode the natural number equals 1. The cyclically changing voltages of adjacent electrodes can be out of phase. The cyclically changing voltages of every other electrode along the array can be in phase.

An embodiment of the present disclosure provides a microfluidic chip, including: a first substrate; wherein the first substrate includes a first base, a first electrode layer on the first base; the first electrode layer includes a plurality of first electrodes at intervals along a first direction, wherein a cross-sectional shape of the first electrode parallel to the first base is a centrosymmetric shape, and the cross-sectional shape includes: a first boundary and a second boundary opposite to each other in the first direction; a shape of the first boundary is a centrosymmetric curve, a distance between two end points of the first boundary in a second direction perpendicular to the first direction is less than a length of the first boundary; the second boundary has a same shape and length as the first boundary, and the first and second boundaries are parallel to each other in the first direction.

A micro-fluidic chip is provided. The micro-fluidic chip includes: a first base substrate; a first electrode on the first base substrate and electrically coupled to a wire at a driving end; a second electrode on a side of the first electrode away from the first base substrate and spaced apart and electrically insulated from the first electrode, the second electrode including a plurality of sub-blocks of the second electrode, and an orthographic projection of the second electrode on the first base substrate being at least partially overlapped with an orthographic projection of the first electrode on the first base substrate; and voltage-dividing resistors coupled to the plurality of sub-blocks of the second electrode in one-to-one correspondence and electrically coupled to a ground wire.

Provided herein, among other aspects, are methods and apparatuses for analyzing particles in a sample. In some aspects, the particles can be analytes, cells, nucleic acids, or proteins and can be contacted with a tag, partitioned into aliquots, detected by a ranking device, and isolated. The methods and apparatuses provided herein may include a microfluidic chip. In some aspects, the methods and apparatuses may be used to quantify rare particles in a sample, such as cancer cells and other rare cells for disease diagnosis, prognosis, or treatment.

Methods are described herein for isolating clonal populations of T cells having a defined genetic modification. The methods are performed, at least in part, in a microfluidic device comprising one or more sequestration pens. The methods include the steps of: maintaining individual T cells (or precursors thereof) that have undergone a genomic editing process in corresponding sequestration pens of a microfluidic device; expanding the T cells into respective clonal populations of T cells; detecting, in one or more T cells of each clonal population, the absence of a cell surface marker that was present in the individual T cells (or precursors thereof); and detecting, in one or more T cells of each clonal population, the presence of a first nucleic acid sequence that is indicative of the presence of an on-target genome edit in the clonal population of T cells. Also described are compositions comprising one or more clonal populations of T cells isolated according to the methods disclosed herein.

In biosciences and related fields, it can be useful to study cells in isolation so that cells having unique and desirable properties can be identified within a heterogenous mixture of cells. Processes and methods disclosed herein provide for encapsulating cells within a microfluidic device and assaying the encapsulated cells. Encapsulation can, among other benefits, facilitate analyses of cells that generate secretions of interest which would otherwise rapidly diffuse away or mix with the secretions of other cells.