Low-cost point-of-care assay device
The present disclosure provides methods and systems for analyzing a liquid sample. A micro-fluidic device to perform an assay of a liquid sample is described that includes a sample application site and a vent outlet in fluid communication with the capillary channel. A cap is provided that is configured to seal both the vent outlet and the sample application site in a shared volume and separate from an outside environment.
1. A micro-fluidic device configured to perform an assay of a liquid sample, the device comprising:
a sample application site in communication with a capillary channel;
a vent outlet in communication with the capillary channel; and
a capping element configured to seal both the vent outlet and the sample application site from an outside environment, wherein the capping element is configured to provide a sealed volume over the sample application site and the vent outlet separate from the outside environment and is configured to provide a sealed volume of a gas shared between the sample application site and the vent outlet.
2. The device according to claim 1 , further comprising a venting channel between the vent outlet and the capillary channel.
3. The device according to claim 1 , further comprising a liquid barrier surrounding the application site, wherein the liquid barrier is disposed between the application site and the vent outlet.
4. The device according to claim 3 , wherein the liquid barrier comprises a raised edge surrounding the application site.
5. The device according to claim 3 , wherein the liquid barrier comprises a depression surrounding the application site.
6. The device according to claim 1 , wherein the capping element comprises a gasket.
7. The device according to claim 1 , wherein the capillary channel is between 20 and 70 microns deep.
8. A method for performing an assay of a liquid sample, the method comprising:
applying a liquid sample to a sample application site in fluid communication with a capillary channel wherein the liquid sample flows via a capillary action force through the capillary channel;
providing venting for the capillary action force through a vent outlet; and
sealing the liquid sample from the outside environment with a capping element, wherein the capping element provides a shared sealed volume around both the sample application site and the vent outlet.
9. The method according to claim 8 , wherein the device further comprises a liquid barrier surrounding the application site and the liquid barrier is disposed between the application site and the vent outlet.
10. The method according to claim 9 , wherein the liquid barrier comprises a raised edge surrounding the application site.
11. The method according to claim 9 , wherein the liquid barrier comprises a depression surrounding the application site.
12. The method according to claim 8 , wherein the capping element comprises a gasket.
13. The method according to claim 8 , wherein the depth of the capillary channel is between 20 and 70 microns deep.
14. The method according to claim 8 , wherein the method further comprises reading at least a portion of the capillary channel to obtain a result.
15. The method according to claim 14 , wherein the method further comprises making a diagnosis based on the obtained result.
16. A system comprising:
(a) a reader; and
(b) a micro-fluidic device configured to perform an assay of a liquid sample and loaded into the reader, the device comprising:
a sample application site in communication with a capillary channel;
a vent outlet in communication with the capillary channel; and
a capping element configured to seal both the vent outlet and the sample application site from an outside environment, wherein the capping element is configured to provide a sealed volume over the sample application site and the vent outlet separate from the outside environment and is configured to provide a sealed volume of a gas shared between the sample application site and the vent outlet.
17. The system according to claim 16 , wherein the reader comprises an illuminator and a detector.
18. The micro-fluidic device of claim 1 , wherein the capping element is dimensioned to cover a surface area on a surface of the device that ranges from 10 to 1000 mm 2 .
19. The micro-fluidic device of claim 18 , wherein the capping contacts only a single surface of the device.
20. The micro-fluidic device of claim 1 , wherein the capping element seals two openings.
21. The micro-fluidic device of claim 1 , wherein the device further comprises a mixing chamber comprising a higher surface area component upon which a reagent is positioned.
22. The micro-fluidic device of claim 2 , wherein the capillary channel is separated from the venting channel by a hydrophobic junction.