Patent ID: 8029743
Filing Date: 2011-10-04
Classification: G01N

Abstract:
1. A microfluidic device, comprising: a separation channel comprising a detection zone; wherein the detection zone is disposed downstream of an injection aperture and upstream of a waste aperture; a semi-permeable filter disposed adjacent to and covering the injection aperture, and configured to preconcentrate and desalt a sample to form a preconcentrated sample plug in the injection aperture during an injection operation; wherein the sample flows downwardly from a sample well through a sample aperture to the separation channel, flows longitudinally in the separation channel from the sample aperture to the injection aperture and flows upwardly in the injection aperture to the filter, and wherein the sample plug flows downwardly from the injection aperture to the separation channel and flows longitudinally in the separation channel from the injection aperture to the detection zone during an electrophoresis operation; wherein the separation channel, the sample aperture, the injection aperture and the waste aperture are formed in a bottom plate, the sample well, the buffer well and the waste well are formed in a well plate, and the filter contacts is disposed between the bottom plate and the well plate; wherein the filter comprises a compressible membrane extending within the buffer well and spaced from the sample well and the waste well; and wherein the filter further comprises a central portion covering the injection aperture and contacting the bottom plate and is uncompressed, and a peripheral portion disposed adjacent to and surrounding the central portion; wherein the peripheral portion is compressed between the bottom plate and the well plate.