METHOD FOR UNIFORM APPLICATION OF FLUID INTO A REACTIVE REAGENT AREA

• US 20100172801A1
• Filed: 01/15/2010
• Published: 07/08/2010
• Est. Priority Date: 06/27/2003
• Status: Abandoned Application

• Current Assignee: Gert Blankenstein, Hai-Hang Kuo, James A. Profitt, Lloyd S. Schulman, Michael J. Pugia, Ralf-Peter Peters
• Original Assignee: Gert Blankenstein, Hai-Hang Kuo, James A. Profitt, Lloyd S. Schulman, Michael J. Pugia, Ralf-Peter Peters
• Inventors: Peters, Ralf-Peter, Kuo, Hai-Hang, Schulman, Lloyd S., Blankenstein, Gert, Pugia, Michael J., Profitt, James A.
• Application Number:
  US12/688,346
• Publication Number:
  US 20100172801A1
• Time in Patent Office: Days
• US Class Current: 422/69
• CPC Class Codes: B01L 2200/0684 Venting, avoiding backpressure, avoid gas bubbles
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0409 centrifugal forces
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/502723 characterised by venting arrangements
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

Analytical results obtained with microfluidic devices are improved by providing structural features in areas containing dry supported reagents, the structural features directing the flow of a sample over the area in a predetermined uniform manner and facilitating the purging of air.

Claims

1. A microfluidic device for assaying a liquid biological sample of 10 μ

L or less,

said device including a space containing microstructures in which a reagent or conditioning agent is immobilized on a substrate and positioned separately from said microstructures

said reagent or conditioning agent deposited on said substrate as a liquid and dried.

2. A microfluidic device of claim 1 wherein said substrate is an absorbent or non-absorbent solid.

3. A microfluidic device of claim 2 wherein said substrate is in the form of paper, film, membrane, or fiber.

4. A microfluidic device of claim 3 said substrate comprises cellulose, nitrocellulose, polyamides, polyesters or glass.

5. A microfluidic device of claim 1 wherein said microstructures are an array of posts positioned adjacent said substrate and aligned at right angle to the flow of said sample.

6. A microfluidic device of claim 1 wherein said microstructures include at least one of the group consisting of ramps, grooves, and weirs to direct flow to said substrate.

7. A microfluidic device of claim 5 wherein said array of posts includes at least two columns or posts staggered to prevent said sample from flowing in a straight line through said space.

8. A microfluidic device of claim 5 wherein said posts have at least one wedge-shaped cutout aligned vertically to said substrate for facilitating movement of the sample onto said substrate.

9. A microfluidic device of claim 5 wherein said substrate is positioned above or below array of posts.

10. A microfluidic device of claim 6 wherein said microstructure is a ramp for directing flow of the sample upward or downward to said substrate disposed on a plateau of said space.

11. A microfluidic device of claim 6 wherein said microstructure is a groove or weir disposed at a right angle to the flow of said sample.

12. A microfluidic device of claim 11 where said groove or weir have at least one wedge-shaped cutout for facilitating distribution of the sample.

13. A microfluidic device for assaying a liquid biological sample of 10 μ

L or less comprising;

(a) an inlet port for receiving said sample;

(b) a capillary passageway in fluid communication with said inlet port, said passageway having dimensions that induce a predetermined capillary force for moving said sample through said passageway;

(c) a well defined by top and bottom surfaces enclosing a side wall, said well having an entry in said sidewall for introducing said sample into said well from said capillary passageway and an air vent positioned on said sidewall, said well containing microstructure for directing flow of said sample;

(d) a reagent or conditioning agent immobilized on a substrate positioned separately said microstructures.

14. A microfluidic device of claim 13 wherein said substrate us an absorbent or non-absorbent solid in the form of paper, films, membrane or fiber.

15. A microfluidic device of claim 14 wherein said substrate comprises cellulose, nitrocellulose, polyamides, polyesters or glass.

16. A microfluidic device of claim 13 wherein said microstructures of claim 13 wherein said microstructures are an array of posts positioned adjacent said substrate and aligned at right angle to the flow of said sample.

17. A microfluidic device of claim 16 wherein said posts have at least one wedge-shaped cutout aligned vertically to said substrate for facilitating movement of the sample onto said substrate.

18. A microfluidic device of claim 13 wherein said microstructures include at least one of the group consisting ramps, grooves, and weirs to direct flow to said substrate.

19. A microfluidic device of claim 18 wherein said microstructure is a ramp for directing flow of the sample upward or downward to said substrate disposed on a plateau of said well.

20. A microfluidic device of claim 18 wherein said microstructure is a groove or weir disposed at a right angle to the flow of said sample.