Simultaneous Concentration and Separation of Proteins in a Nanochannel

Abstract

Balancing the forces: Conductivity gradient focusing in a nanochannel achieves simultaneous separation and concentration of proteins without a temperature gradient, membrane, matrix, ampholytes, or external pump. The electrophoretic force (see picture; red arrow) that dominates at the low-salt side (−) balances the electro-osmotic force (blue) at the high-salt side (+).