Methods and Materials to Generate Antibody Repertoire Libraries

Abstract

Droplet microfluidics is a powerful tool to investigate cell populations. Using droplet microfluidics, individual cells can be rapidly compartmentalized into distinct droplets and analyzed to capture cell-to-cell variation across millions of cells. In the human body there are over one billion immune B-cells in circulation, each of which can encode for the expression of a unique antibody. Antibodies are attractive candidates in the development of new therapeutics, but there are few methods capable of capturing the full diversity of antibodies generated during an immune response in a format that can be screened to identify promising therapeutic candidates. Here, I introduce a method to encapsulate over one million B-cells in microfluidic droplets and efficiently link the genetic sequences that encode for the heavy and light chain variable regions of the antibodies produced by individual B-cells. These linked sequences can be directly engineered into bacteriophage to generate phage display libraries that recapitulate the antibody response of an organism. My method is enabled in part by a biocompatible film-forming surfactant that I developed that robustly stabilizes droplets and prevents their coalescence during the repeated cycles of heating and cooling required to amplify DNA during polymerase chain reaction (PCR). The surfactant forms a DNA-impermeable capsule around the droplet. Other chemistries for the construction of capsules with tunable permeability for macromolecular species are also included.