Electropipettor and compensation means for electrophoretic bias
View Patent ↗A channel ( 140 ) is divised into portions ( 142, 144 ). The sidewalls of each channel portion ( 142, 144 ) have surface charges of opposite polarity. The two channel portions ( 142, 144 ) are physically connected together by a salt bridge ( 133 ), such as a glass frit or gel layer. The salt bridge ( 133 ) separates the fluids in channel ( 140 ) from an ionic fluid reservoir ( 135 ). To impart electroosmotic and electrophoretic forces along the channel ( 140 ) between parts A and B, respectively. Additionally, a third electrode ( 137 ) is placed in the reservoir ( 135 ).
1. A microfluidic device comprising:
a planar substrate having at least a first microfluidic channel disposed therein, the first microfluidic channel having at least one cross-sectional dimension of less than about 100 microns; and
a pipettor extending from the substrate and having a first capillary channel disposed therein, the first capillary channel having at least one cross-sectional dimension of less than about 100 microns and being fluidly connected at a first end to the first microfluidic channel.
2. The microfluidic device of claim 1 , wherein the pipettor comprises a capillary tube.
3. The microfluidic device of claim 1 , wherein the substrate comprises at least first and second interconnected microfluidic channels disposed therein.
4. The microfluidic device of claim 1 , wherein the pipettor is formed from at least a portion of the substrate.
5. The microfluidic device of claim 1 , wherein the substrate comprises glass.
6. The microfluidic device of claim 1 , wherein the substrate comprises a polymeric material.
7. The microfluidic device of claim 1 , wherein the capillary channel has a cross-sectional dimension of between about 1 and about 50 μm.
8. The microfluidic device of claim 1 , wherein the pipettor comprises an electropipettor.
9. The microfluidic device of claim 1 , wherein the capillary channel has a cross-sectional area of between about 10 and about 1000 μm 2 .
10. The microfluidic device of claim 1 , wherein the capillary channel has a cross-sectional area of between about 10 and about 100 μm 2 .
11. The microfluidic device of claim 1 , wherein the capillary channel has a diameter of about 30 μm.
12. The microfluidic device of claim 1 , wherein the substrate comprises at least three or more intersecting microfluidic channels disposed therein.