Abstract: An isotachophoresis (ITP) apparatus having a first zone configured to contain a solution comprised of a trailing electrolyte (TE); a second zone configured to contain solution containing a leading electrolyte (LE); a flow channel connecting the first zone and the second zone; and a first filter having a pore size sufficient to entrap an analyte, the first filter being integrated within the first zone, and in fluid communication with the flow channel, wherein the flow channel is in a distinct direction with respect to the filtration flow, is disclosed herein. A system comprised of a microfluidic device comprised of a flow channel is further disclosed. A method of electrophoresis-sample preparation is further disclosed herein.