Abstract: In biosciences and related fields, it can be useful to modify surfaces of apparatuses, devices, and materials that contact biomaterials such as biomolecules and biological micro-objects. Described herein are surface modifying and surface functionalizing reagents, preparation thereof, and methods for modifying surfaces to activate T Lymphocytes.

Abstract: Methods are described herein for screening an antibody producing cell within a microfluidic environment. The antibody producing cell may be a B cell lymphocyte, which may be a memory B cell or a plasma cell. An antigen of interest may be brought into proximity with the antibody producing cell and binding of the antigen by an antibody produced by the antibody producing cell may be monitored. Methods of obtaining a sequencing library from an antibody producing cell are also described.

Abstract: This application describes systems and methods for assaying micro-objects in a microfluidic device. These methods include contacting a reagent with a micro-object by introducing a reagent in a first fluidic medium to a flow region of a microfluidic device, wherein the microfluidic device comprises the flow region and a chamber comprising a proximal opening fluidically connecting the chamber to the flow region, diffusing the reagent from the flow region into the chamber; introducing a micro-object into the flow region of the microfluidic device, and diffusing the reagent from the chamber to the flow region to contact the reagent with the micro-object within the flow region. Other embodiments are described.

Abstract: 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.

Abstract: Some configurations of a microfluidic apparatus can comprise a fluidic circuit of interconnected fluidic structures into which a plurality of different media can be introduced or extracted. A variety of operations can be performed with the different media including isolating with a second medium one or more of the fluidic structures that is filled partially or fully with a first medium. Discrete volumes of a medium can be moved through the isolating second medium to deliver materials or micro-objects to or remove micro-objects or materials from a fluidic structure that is otherwise isolated by the second medium. Some configurations of a microfluidic apparatus can isolate microfluidic structures in a microfluidic apparatus using flow rates or blocking structures, and some configurations can manage bubbles in fluidic structures.

Abstract: In situ-generated microfluidic isolation structures incorporating a solidified polymer network, methods of preparation and use, compositions and kits therefor are described. The ability to introduce in real time, a variety of isolating structures including pens and barriers offers improved methods of micro-object manipulation in microfluidic devices. The in situ-generated isolation structures may be permanently or temporarily installed.

Abstract: Systems, methods and kits are described for culturing one or more biological cells in a microfluidic device, including provision of nutrients and gaseous components configured to enhance cell growth, viability, portability, or any combination thereof. In some embodiments, culturing a single cell may produce a clonal population in the microfluidic device.

Abstract: Proto-antigen-presenting surfaces and related kits, methods, and uses are provided. The proto-antigen-presenting surface can comprise a plurality of primary activating molecular ligands comprising a major histocompatibility complex (MHC) molecule configured to bind to a T cell receptor (TCR) of a T cell and a plurality of co-activating molecular ligands each including a TCR co-activating molecule or an adjunct TCR activating molecule, wherein an exchange factor is bound to the MHC molecules. Exchange factors include, e.g., dipeptides such as GL, GF, GR, etc. Proto-antigen-presenting surfaces can be used to rapidly prepare antigen-presenting surfaces comprising one or more peptide antigens of interest by contacting the proto-antigen-presenting surface with one or more peptide antigens so as to displace the exchange factor. As such, the disclosure facilitates rapid evaluation of the immunogenicity of peptide antigens for activating T lymphocytes.

Abstract: A method of processing and storing biological cells includes introducing a flowable medium into a microfluidic device, the flowable medium including biological cells; sequestering one or more biological cells from the flowable medium in one or more isolation regions of the microfluidic device; and freezing the microfluidic device including the one or more biological cells sequestered therein.

Abstract: Methods, systems, and kits for determining a level of dissolved oxygen within a microfluidic device are provided. The microfluidic device can be suitable for cell culture. The methods, systems, and kits can further be used to determine a level of oxygen consumption in a population of biological micro-objects. In particular, the methods, systems, and kits of the present disclosure rely on flowing a fluidic medium containing a dye and a supplied partial pressure of oxygen into the microfluidic device for a period of time, wherein fluorescence emitted by the dye changes based on availability of oxygen proximate to the dye; taking a fluorescence image of an area of interest within the chamber; and correlating fluorescence of the fluorescence image of the area of interest to a reference to determine an observed partial pressure of the oxygen in the area of interest.

Abstract: Metabolic engineering has developed microbial cell factories as sustainable alternatives to chemical synthesis from petroleum feedstocks or harvesting of animals and plants, but current methods can be a costly and labor-intensive commitment. Methods are described herein for microfluidic methods of screening thousands of variant cells in order to reduce time and uncertainty to provide improved strains.

Abstract: Reagents for stabilizing the nucleic acids of a biological cell, compositions, kits and methods of use thereof are described. The stabilization reagents may prepare the nucleic acids within the biological cell for storage and preserve the representative population of the nucleic acids for later isolation and analysis.

Abstract: Biological activity in holding pens in a micro-fluidic device can be assayed by placing in the holding pens capture objects that bind a particular material of interest produced by the biological activity. The biological material of interest that binds to each capture object can then be assessed, either in the micro-fluidic device or after exporting the capture object from the micro-fluidic device. The assessment can be utilized to characterize the biological activity in each holding pen. The biological activity can be production of the biological material of interest. Thus, the biological activity can correspond to or arise from one or more biological cells. Biological cells within a holding pen can be clonal cell colonies. The biological activity of each clonal cell colony can be assayed while maintaining the clonal status of each colony.

Abstract: In biosciences and related fields, it can be useful to modify surfaces of apparatuses, devices, and materials that contact biomaterials such as biomolecules and biological micro-objects. Described herein are surface modifying and surface functionalizing reagents, preparation thereof, and methods for modifying surfaces of wells within a well plate to activate lymphocytes, including but not limited to T lymphocytes, in a controllable and reproducible manner.

Abstract: A method of preparing an antibody therapeutic is provided comprising: (a) providing a dissociated cell sample from at least one solid tumor sample obtained from a patient; (b) loading the dissociated cell sample into a microfluidic device having a flow region and at least one isolation region fluidically connected to the flow region; (c) moving at least one B cell from the dissociated cell sample into at least one isolation region in the microfluidic device, thereby obtaining at least one isolated B cell; and (d) using the microfluidic device to identify at least one B cell that produces antibodies capable of binding to cancer cells. The cancer cells can be the patient's own cancer cells. Also provided are methods of treating patients, methods of labeling or detecting cancer, engineered T or NK cells comprising antibodies or fragments thereof, and engineered antibody constructs.