Abstract: This invention provides methods and compositions, e.g., to reduce interference from non-specific binding sample constituents in a migration shift assay. Interference due to non-specific binding of sample constituents to an affinity substance (e.g., an affinity molecule or a conjugate of an affinity molecule and a charged carrier molecule) is prevented by, e.g., binding the constituents to charged polymers such as heparin sulfate. The present invention also provides methods to concentrate an analyte of interest with high concentration and to detect the analyte with high sensitivity, and further to optimize the reaction conditions for easily concentrating the analyte. Such objects of the present invention are attained, for example, by concentrating a complex of the analyte and a conjugate which is formed by contacting the analyte in a sample with an affinity molecule bound to a charged carrier molecule such as DNA.

Abstract: This invention provides methods and systems for injection of analytes into a separation channel for resolution and detection. Samples can be preconditioned and concentrated by isotachophoresis (ITP) before the injection is triggered by a detected voltage event. Separation of analytes from other sample constituents can be enhanced using skewing channel ITP.

Abstract: Methods for screening a compound for enzyme inhibition activity include providing at least one sample mixture to a microfluidic device, applying vacuum pressure to the sample mixture, flowing the sample mixture along a microchannel of the microfluidic device, separating at least two components of the sample mixture based upon a net charge difference between the product and at least one other material to produce separated material, detecting at least one of the separated materials, and determining enzyme inhibition activity based on the detection of the separated material. Kits for screening a compound for enzyme inhibition activity include a first multiwell plate having a specific plurality of enzymes disposed within a first plurality of wells and a second multiwell plate having a plurality of enzyme substrates disposed with a second plurality of wells, a phosphate source and a cofactor disposed within each well of the second plate.

Abstract: This invention provides methods and systems for injection of analytes into a separation channel for resolution and detection. Samples can be preconditioned and concentrated by isotachophoresis (ITP) before the injection is triggered by a detected voltage event. Separation of analytes from other sample constituents can be enhanced using skewing channel ITP.

Abstract: Methods for screening a compound for enzyme inhibition activity include providing at least one sample mixture to a microfluidic device, applying vacuum pressure to the sample mixture, flowing the sample mixture along a microchannel of the microfluidic device, separating at least two components of the sample mixture based upon a net charge difference between the product and at least one other material to produce separated material, detecting at least one of the separated materials, and determining enzyme inhibition activity based on the detection of the separated material. Kits for screening a compound for enzyme inhibition activity include a first multiwell plate having a specific plurality of enzymes disposed within a first plurality of wells and a second multiwell plate having a plurality of enzyme substrates disposed with a second plurality of wells, a phosphate source and a cofactor disposed within each well of the second plate.