Electropipettor and compensation means for electrophoretic bias

A microfluidic system comprising:

• a body structure;
• at least first and second microscale channels disposed in the body structure, the first and second channels being in fluid communication at a first intersection, the first channel being at least twice as deep as the second channel, and wherein the first channel comprises an aspect ratio (width:depth) of greater than about 5;
• and
• an electrokinetic material transport system for moving materials through the first and second microscale channels.

A microfluidic system comprising:

• a body structure;
• at least first and second microscale channels disposed in the body structure, the first and second channels being in fluid communication at a first intersection, the first channel being at least twice as deep as the second channel wherein the first channel comprises first and second material regions disposed therein, the first material region having an ionic concentration different from the second material region;
• and
• an electrokinetic material transport system for moving materials through the first and second microscale channels.

A microfluidic system comprising:

• a body structure having at least first and second microscale channels disposed therein, wherein:
• the first channel communicates with the second channel at a first intersection;
• the first channel comprises at least two different material regions flowing therethrough, the two different material regions having different ionic concentrations;
• and
• the first channel is at least twice as deep as the second channel;
• and
• an electrokinetic material transport system for moving materials through the first and second microscale channels.

A method of electrokinetically transporting a material stream through a first microscale channel, wherein the first channel is intersected by a second channel and the material stream comprises at least first and second material regions of differing ionic concentrations, comprising:

• providing the first microscale channel with a depth that is at least twice a depth of the second channel;
• introducing the at least first and second material regions into the first channel;
• and
• applying an electrical field across a length of the first microscale channel to electrokinetically move the at least first and second material regions through the first channel.