Capillary barriers for staged loading of microfluidic devices

Patent metadata

Field	Value
Publication number	US-11851647-B2
Application number	US-202016998839-A
Country	US
Kind code	B2
Filing date	Aug 20, 2020
Priority date	Mar 14, 2013
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

Various aspects of the present disclosure are directed toward methods and apparatuses for interacting a first liquid and a second liquid in one or more fluidic channels of a capillary structure. The methods and apparatuses can include providing at least one capillary barrier that positions a meniscus of the first liquid at a fluid-interface region using capillary forces within the capillary structure. Additionally, a path is provided along one of the channels for the second liquid to flow toward the fluid-interface region. Additionally, gas pressure is released, via a gas-outflow port, from the fluid-interface region while flow of the first liquid is arrested. Further, the first liquid and the second liquid contact in the fluid-interface region with the capillary barrier holding the first liquid at the fluid-interface region.

First claim

What is claimed is:

1. An apparatus, comprising:
(a) a structure comprising:
(i) a first microfluidic channel to guide a first liquid toward a fluid-interface region;
(ii) a second microfluidic channel to guide a second liquid toward the fluid-interface region; and
(iii) a capillary barrier to position a meniscus of the first liquid at the fluid-interface region using capillary force;

(b) a first open reservoir connected to the first microfluidic channel;
(c) a second open reservoir connected to the first open reservoir via the second microfluidic channel; and
(d) a third open reservoir connected to the first microfluidic channel; wherein the third open reservoir is present within a fluidic path, wherein the fluidic path interconnects the first open reservoir and the fluid-interface region.

2. The apparatus of claim 1 , further comprising an escape path fluidically coupled to the fluid-interface region.

3. The apparatus of claim 1 , wherein the second open reservoir is connected to the first open reservoir via both the first microfluidic channel and the second microfluidic channel.

4. The apparatus of claim 1 , wherein the first open reservoir comprises a leading electrolyte buffer.

5. The apparatus of claim 1 , wherein the second open reservoir comprises a trailing electrolyte buffer.

6. The apparatus of claim 1 , wherein the third open reservoir comprises an extraction buffer.

7. The apparatus of claim 1 , wherein the first open reservoir comprises a leading electrolyte buffer for isotachophoresis (ITP); and the second open reservoir comprises a trailing electrolyte buffer for ITP.

8. The apparatus of claim 1 , wherein the second microfluidic channel comprises a sample.

9. The apparatus of claim 8 , wherein the sample comprises a nucleic acid.

10. The apparatus of claim 9 , wherein the nucleic acid comprises DNA.

11. The apparatus of claim 9 , wherein the nucleic acid comprises RNA.

12. The apparatus of claim 1 , wherein the first microfluidic channel comprises a separation buffer for ITP.

13. The apparatus of claim 1 , wherein either the first open reservoir or the second open reservoir comprises an electrode.

14. The apparatus of claim 1 , wherein the first open reservoir comprises a first electrode and the second open reservoir comprises another electrode.

15. The apparatus of claim 1 , wherein the first microfluidic channel comprises a leading electrolyte buffer with an edge that borders the fluid-interface region.

16. The apparatus of claim 1 , wherein the second open reservoir is connected to the second microfluidic channel via a third microfluidic channel comprising trailing electrolyte buffer.

17. The apparatus of claim 1 , wherein the third open reservoir is connected to the second microfluidic channel via the first microfluidic channel and wherein the first microfluidic channel comprises leading electrolyte buffer.

18. The apparatus of claim 1 , further comprising a vacuum port positioned to release gas pressure from the fluid-interface region.

19. The apparatus of claim 1 , wherein the capillary barrier is at least in part defined by a change in a cross-sectional area, wherein the change in the cross-sectional area is sufficient to arrest flow of the first liquid at the fluid-interface region.

20. The apparatus of claim 1 , wherein the first microfluidic channel comprises leading electrolyte buffer and the first open reservoir comprises high buffering capacity leading electrolyte buffer.

21. A method comprising:
providing an apparatus including a structure with a first microfluidic channel to guide a first liquid toward a fluid-interface region, with a second microfluidic channel to guide a second liquid toward the fluid-interface region, and with a capillary barrier to position a meniscus of the first liquid at the fluid-interface region using capillary force;
providing a first open reservoir connected to the first microfluidic channel, a second open reservoir connected to the first open reservoir via the second microfluidic channel, and a third open reservoir connected to the first microfluidic channel; wherein the third open reservoir is present within a fluidic path, and the fluidic path interconnects the first open reservoir and the fluid-interface region; and
causing the first liquid to flow in the first microfluidic channel until the capillary barrier arrests flow of the first liquid in the first microfluidic channel.

22. The method of claim 21 , further comprising causing the second liquid to flow in the second microfluidic channel until the capillary barrier arrests flow of the second liquid in the second microfluidic channel.

23. The method of claim 22 , further comprising releasing gas pressure via a gas-outflow port, while flow of the first liquid is arrested.

24. The method of claim 21 , wherein the first liquid is a leading electrolyte buffer.

25. The method of claim 21 , wherein the second microfluidic channel comprises a sample.

26. The method of claim 21 , further comprising causing the first liquid and the second liquid to contact in the fluid-interface region with the capillary barrier holding the first liquid at the fluid-interface region.

27. The method of claim 21 , wherein the apparatus further comprises a third microfluidic channel comprising trailing electrolyte (TE) buffer.

28. The method of claim 21 , wherein the second open reservoir comprises a trailing electrolyte buffer.

29. A method comprising:
(a) providing the apparatus of claim 1 , wherein:
the first open reservoir comprises a leading electrolyte buffer; and
the first microfluidic channel comprises a leading electrolyte buffer; and

(b) introducing a sample comprising nucleic acids into the second microfluidic channel such that the sample is situated between the trailing electrolyte buffer and the leading electrolyte buffer.

30. The method of claim 29 , wherein the method comprises moving the nucleic acids from the second microfluidic channel through the first microfluidic channel by applying an electrical current between the first and second open reservoirs.

31. The method of claim 29 , further comprising extracting nucleic acids from the third open reservoir.

32. An apparatus, comprising:
(a) a structure comprising:
(i) a first microfluidic channel to guide a first liquid toward a fluid-interface region;
(ii) a second microfluidic channel to guide a second liquid toward the fluid-interface region; and
(iii) a capillary barrier to position a meniscus of the first liquid at the fluid-interface region using capillary force;

(b) a first open reservoir connected to the first microfluidic channel, wherein the first open reservoir or the first microfluidic channel comprises leading electrolyte buffer;
(c) a second open reservoir connected to the first open reservoir via the second microfluidic channel; and
(d) a third open reservoir connected to the first microfluidic channel; wherein the third open reservoir is present within a fluidic path, wherein the fluidic path interconnects the first open reservoir and the fluid-interface region.

33. A method comprising:
providing the apparatus of claim 32 , and
introducing the second liquid into the second microfluidic channel, wherein the second liquid comprises a sample comprising nucleic aci

Assignees

• Univ Leland Stanford Junior

Inventors

• Santiago Juan G
• Marshall Lewis A
• Rogacs Anita

Classifications

• C12N15/101 Primary

  by chromatography, e.g. electrophoresis, ion-exchange, reverse phase · CPC title

• B01D57/02

  by electrophoresis (treatment of water, waste water, sewage or sludge by electrophoresis C02F1/469; electrophoretic production of compounds or non-metals C25B7/00; investigating or analysing materials by using electrophoresis G01N27/26) · CPC title

• B01L3/502715

  characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces · CPC title

• B01L3/502723 Primary

  characterised by venting arrangements · CPC title

• B01L3/502738

  characterised by integrated valves (throttle valves in microfluidic sample containers B01L3/502746) · CPC title