Claims
- 1. In a microfluidics device having a supply channel for holding a sample, a drain channel, and a separation channel for containing an electrolyte buffer, where said supply and drain channels intersect said separation channel at a supply port and a drain port, respectively, which ports define a sample-volume region in the separation channel between the two ports, and first, second, third, and fourth reservoirs communicating with the supply channel, the drain channel, and upstream and downstream ends of the separation channel, respectively, such that applying an electrokinetic or pneumatic force between the first and second reservoirs is effective to move a sample from the first reservoir through the sample-volume region in the separation channel and into the drain channel, and applying an electrokinetic or pneumatic force between the third and fourth reservoirs is effective to move a sample in the sample-volume region in the separation channel in a downstream direction, an improvement for sample volume control, comprising at least one of the following channel configurations:
(a) first and second peripheral channels connecting the supply channel to upstream and downstream regions of the separation channel, respectively, on opposite sides of the sample-volume region, such that applying an electrokinetic or pneumatic force between the first and second reservoirs is effective to move a sample from the first reservoir through the supply channel, the sample-volume region in the separation channel and into the drain channel, via the supply and drain channels, and to move electrolyte solution contained in the first and second peripheral channels and upstream and downstream regions of the separation channel toward the sample-volume region and into the drain channel, thereby shaping the sample in the sample-volume region during sample loading; and (b) second and third peripheral channels connecting the supply channel and the drain channel, respectively, to a downstream region of the separation channel, respectively, such that applying an electrokinetic or pneumatic force between the third and fourth reservoirs is effective to move a sample in the sample-volume region in the separation channel in a downstream direction, and to move electrolyte solution contained in the upstream region of the separation channel through the second and third peripheral channels, thereby moving sample contained in the sample and drain channels away from the sample-volume region of the separation channel during sample injection.
- 2. The improvement of claim 1, wherein the force applied between the reservoirs is an electrokinetic force produced by placing an electric voltage potential difference between the reservoirs.
- 3. The improvement of claim 1, which includes said first and second peripheral channels, for shaping sample in the sample-volume region during sample loading, and said third peripheral channel, for cooperating with the second peripheral channel during sample injection, to move sample contained in the sample and drain channels away from the sample-volume region of the of the separation channel.
- 4. The improvement of claim 3, wherein the force applied between the reservoirs is an electrokinetic force by placing an electric voltage potential difference between the reservoirs.
- 5. The improvement of claim 3, which further includes a fourth peripheral channel connecting the drain channel to an upstream portion of the separation channel.
- 6. The improvement of claim 1, wherein the sample and drain ports are axially aligned within the separation channel, and the sample-volume region includes the region between the two ports.
- 7. The improvement of claim 1, wherein the sample and drain ports are longitudinally offset along the separation channel, and the sample-volume region includes the region of the separation channel between the two ports, including the ports themselves.
- 8. The improvement of claim 1, which includes said first and second peripheral channels, and which further includes a second pair of peripheral channels, each of which extends from a first region point along the sample channel, adjacent the first reservoir, and a region along the sample channel adjacent the intersection of the sample channel with the separation channel, such that applying an electrokinetic or pneumatic force between the first and second reservoirs is effective to move a sample from the first reservoir through the sample channel toward the separation channel, and to move electrolyte solution contained in the second pair of peripheral channels from the first to the second regions in the sample channel, thereby shaping the sample in the sample channel as if is moved into the sample-volume-region of the separation channel.
- 9. The improvement of claim 1, wherein at least one of the first and second peripheral channels has higher resistance to flow fluid flow, when an electrokinetic or pneumatic force is applied between the first and second reservoirs, than the resistance to liquid flow in the sample channel.
- 10. The improvement of claim 1, wherein at least one of the second and third peripheral channels has a higher resistance to fluid flow, when an electrokinetic or pneumatic force is applied between the third and fourth reservoirs, than the resistance to fluid flow in the separation channel.
- 11. The improved microfluidics system for use in sample handling, comprising
(a) the improved microfluidics device of claims 1-10, (b) electrodes adapted to contact liquid contained in the device reservoirs, and (c) a control unit for controlling the electric potential difference between the first and second reservoirs, during sample loading, and between the third and fourth and reservoirs, during sample injection.
Parent Case Info
[0001] This application claims the benefit of U.S. Provisional Application No. 60/190,277 filed Mar. 17, 2000 and U.S. Provisional Application No. 60/197,323 filed Apr. 14, 2000, both of which are incorporated herein by reference in their entirety.
Provisional Applications (2)
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Number |
Date |
Country |
|
60190277 |
Mar 2000 |
US |
|
60197323 |
Apr 2000 |
US |