Patent ID: 7704360

Claim:
A device for separating constituents of a sample, said device comprising: (a) a fluid flow path; (b) two electrophoretic separation elements positioned at spatially separated regions along said fluid flow path, each electrophoretic separation element of said two electrophoretic separation elements comprising: (i) an electric field generation element for applying an electric field across the region of said fluid flow path at which said electrophoretic separation element is positioned, wherein said electric field causes charged constituents of said sample to migrate out of said fluid flow path; and ii) a trapping element for retaining said charged constituents that have migrated out of said fluid flow path, wherein said trapping element comprises a first compartment separated from said fluid flow path; and (c) a pH adjustment element located between said two electrophoretic separation elements, wherein said pH adjustment element changes the pH of fluid in said fluid flow path between said two electrophoretic separation elements.