Separation and Enrichment of Low Abundant Proteins in a Microchannel Using Isotachophoresis

Abstract

Low abundance of circulating proteins in blood is one of the major challenges in on-chip purification and extraction from highly abundant proteins like Albumins. In this presentation, we will demonstrate the separation of low abundant proteins from highly abundant albumin in a microchannel using isotachophoresis (ITP), non-linear electrophoresis. A PMMA (poly-methylemethacrylate) microchannel with a change in cross-sectional area was made using photolithographic processes and solvent assisted thermal bonding. The bonding strength of the microchannel was tested using a universal testing machine and pressurized flow through the channel. The leading electrolyte (LE) was prepared from KOH, Urea, Triton X-100, PVP by adjusting pH to 4.0 with acetic acid. The terminating electrolyte (TE) was 20 mM Acetic Acid, PVP, and Triton X-100. PVP suppresses electroosmotic flow while the urea and Triton X-100 remove precipitates that form during ITP. The ITP experiments were conducted by applying an electric potential of 200 V across the channel and images of sample migrations were taken using a fluorescent microscope.