Abstract: Disclosed herein are methods for performing assays, including general functional assays, on a biological cell. Also disclosed herein are methods of barcoding the 5? ends of RNA from a biological cell and methods of preparation of expression constructs from the barcoded RNA. The barcoded RNA can encode proteins of interest, such as B cell receptor (BCR) heavy and light chain sequences. The expression constructs can be generated individually or in a paired/multiplexed manner, allowing rapid re-expression of individual proteins or protein complexes.

Abstract: Microfluidic devices having an electrowetting configuration and an optimized droplet actuation surface are provided for processing biological cells, e.g., for use in nucleic acid library preparation and/or synthesis (including amplification). The devices include a dielectric layer, a hydrophobic layer covalently bonded to the dielectric layer, and a first electrode. Methods of nucleic acid library preparation and/or synthesis can involve providing reagents to cells or nucleic acids by merging appropriate droplets on a droplet actuation surface within a water-immiscible organic liquid and can be performed in the presence of appropriate surfactants. The hydrophobic layer features self-associating molecules covalently bonded to a surface of the dielectric layer in a manner that produces a densely-packed monolayer that resists intercalation and or penetration by polar molecules or species.

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.