Disclosed herein are methods and devices for antigen-specific T cell identification or neoantigen identification. Also disclosed herein are devices for separating and isolating antigen-specific T cells or other particles of a certain size from a population of particles of different sizes. Also describe herein are methods and devices for the separation and isolation of barcoded T cells from other nanoparticles containing barcodes for subsequent analysis and further processing of a viable T cell.