Microfluidic apparatus and method for purification and processing

An integrated microfluidic device comprising microchannels formed in a generally planar substrate, said device comprising:

• an enrichment microchannel comprising an enrichment channel portion containing an enrichment medium, said enrichment channel portion having a first inlet and a first fluid outlet;
• a main electrophoretic microchannel enclosing a main electrophoretic flowpath, said main electrophoretic microchannel being connected in fluid-conducting relation to said first fluid outlet, and said main electrophoretic microchannel comprising a detection region;
• means for moving a sample into said enrichment channel portion by way of said first inlet and out from said enrichment channel portion by way of said first fluid outlet, whereby at least a fraction of a component of interest in the sample is retained by said enrichment medium,
• a discharge channel connected in fluid communication with said first fluid outlet at a point upstream from said main electrophoretic flowpath, for discharging a portion of said sample other than said fraction away from said main electrophoretic flowpath;
• and
• means for moving at least a portion of the fraction out from said enrichment channel portion by way of said first fluid outlet and into said main electrophoretic microchannel.

An integrated microfluidic device comprising microchannels formed in a generally planar substrate, said device comprising:

• an enrichment microchannel comprising an enrichment channel portion containing an enrichment medium, said enrichment channel portion having a first inlet and a first fluid outlet;
• a main electrophoretic microchannel enclosing a main electrophoretic flowpath, said main electrophoretic microchannel being connected in fluid-conducting relation to said first fluid outlet, and said main electrophoretic microchannel comprising a detection region;
• means for moving a sample into said enrichment channel portion by way of said first inlet and out from said enrichment channel portion by way of said first fluid outlet, whereby at least a fraction of a component of interest in the sample is retained by said enrichment medium;
• a discharge channel connected in fluid communication with said first fluid outlet at a point upstream from said main electrophoretic flowpath, for discharging a portion of said sample other than said fraction away from said main electrophoretic flowpath;
• means for moving at least a portion of the fraction out from said enrichment channel portion by way of said first fluid outlet and into said main electrophoretic microchannel;
• and
• a plurality of input microchannels connected in fluid relation to said first inlet, said plurality of input microchannels comprising at least a sample input microchannel and an elution input microchannel.

A method of enriching a target in a sample comprising:

• providing a microfluidic device having at least one microchannel formed in a generally planar substrate, wherein at least one of the microchannels comprises an enrichment channel portion having at least an inlet and an outlet;
• loading the sample into said enrichment channel portion through said inlet;
• loading at least one reagent including an enrichment medium containing specific binding moieties which bind to the target into said enrichment channel portion;
• capturing said targets with said specific binding moieties to form a complex between said target and said specific binding moieties;
• and
• washing said enrichment channel portion to remove non-bound sample.