Volume metering capillary gap device for applying a liquid sample onto a reactive surface

• US 4,761,381 A
• Filed: 02/26/1987
• Issued: 08/02/1988
• Est. Priority Date: 09/18/1985
• Status: Expired due to Term

• Current Assignee: Miles, Inc. (Bayer AG)
• Original Assignee: Miles, Inc. (Bayer AG)
• Inventors: Pugh, Jerry, Morris, James R., Blatt, Joel M., Wogoman, Frank W., Heiland, Robert
• Primary Examiner(s): Richman, Barry S.
• Assistant Examiner(s): ALEXANDER, LYLE
• Application Number:
  US07/020,185
• Time in Patent Office: 523 Days
• Field of Search: 422/55-58, 422/61, 422/72, 422/102, 436/165-166, 356/244, 356/246, 435/805, 435/810, 350/534-536
• US Class Current: 436/165
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0822 Slides
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence

Abstract

A method for controlling a liquid volume flowing onto a reactive surface which includes a sample application port, two systems of capillary channels, a reaction chamber, and an overflow chamber. The liquid sample to be analyzed is applied to the sample application port which gives the liquid entry to a capillary channel leading to the reaction chamber which contains a material capable of detecting the component of interest in the liquid. When the reaction chamber is filled, the remaining liquid will flow through another capillary channel to an overflow chamber. The capillary channel leading to the overflow chamber is controlled so that liquid cannot flow back into the reaction chamber.

Claims

1. A flow metering capillary device for controlled fluid flow of test liquid comprising oppositely disposed top and bottom surface layers defining therebetween a capillary zone of intended liquid transport of a test liquid, said top and bottom surface layers being spaced apart at a distance no greater than which will maintain a capillary flow of said test liquid therebetween and wherein said capillary zone is divided into a sample test chamber containing interactive material capable of reaction with a component of said test liquid to provide a detectable response and an overflow chamber for excess test liquid,

an overflow proportioning channel located between said sample test chamber and said overflow chamber which functions to permit overflow of test liquid from the sample test chamber to the overflow chamber and as a capillary lock to break connection between test liquid in the sample chamber and test liquid in the overflow chamber and which prevents backflow of the test liquid from the overflow chamber to the sample chamber, and

means defining a sample application port for introduction of said test liquid into said capillary zone, said sample application port being in communication with said sample test chamber and contiguous to said overflow proportioning channel.

2. The device as set forth in claim 1, wherein said distance is between about 0.007 and about 0.08 centimeter.

3. The device as set forth in claim 1, wherein the top surface layer is transparent.

4. The device as set forth in claim 1, wherein the interactive material is a reagent impregnated responsive layer.

5. The device as set forth in claim 1, further comprising an adhesive layer interposed between said surface layers for sealing said surface layers together.

6. The device as set forth in claim 1, wherein said channel and said chambers are formed in the surface layers.

7. The device as set forth in claim 1, which said chambers are of substantially rectangular shape.

8. The device as set forth in claim 1, wherein the chambers are of a contoured configuration.

9. The device as set forth in claim 1, which additionally has present an absorbent wicking layer between said surface layers.

10. The device as set forth in claim 1, wherein the interactive material is a multiple reagent layer.

11. The device as set forth in claim 1, wherein a surface of the capillary zone is coated with a surface active agent.

12. The device as set forth in claim 1, wherein said sample application port is located at a side of said device.

13. The device as set forth in claim 1, wherein said sample application port is located at an end of said device.

14. The device as set forth in claim 1, wherein said sample test chamber and said overflow chamber are of relatively larger dimensional area and said channel connecting said chambers is of relatively smaller dimensional area, said channel being adjacent the sample application port.

15. The device as set forth in claim 1, wherein said sample application port comprises a sample entry port located at a side of said device, said port being a relatively narrow passageway connected to a sample test chamber of relatively larger area, said overflow chamber being connected to the relatively narrow passageway by an overflow metering channel.

16. The device of claim 1 which includes means for removing excess test liquid from said overflow chamber.

17. The device as set forth in claim 16, wherein said top surface layer has a means defining relief port for venting air from said sample test chamber and said means for removing excess test liquid comprises a means defining an overflow port connected to said overflow chamber for removing excess test liquid.

18. The device as set forth in claim 1, wherein the device is rectangular in shape having a major axis and a minor axis.

19. The device as set forth in claim 18, wherein the dimensions of the device are about 3.7 cm long by 1 cm wide.

20. The device as set forth in claim 1, wherein the sample application port has a circular ring around it which rises above an upper surface of the port defining means.

21. The device as set forth in claim 20, wherein the thickness of the device is 0.05 to 0.25 cm.

22. A flow metering capillary device for controlled fluid flow comprising a top surface layer, a bottom reagent interactive layer and a spacer layer positioned therebetween and defining a capillary zone of intended liquid transport of a dimension no greater than that which will maintain a capillary flow of liquid introduced into said zone, and wherein said capillary zone is divided into a sample test chamber containing interactive material capable of reacting with a component of said liquid to provide a detectable response and an overflow chamber for excess liquid,

an overflow proportioning channel located between said sample test chamber and said overflow chamber which functions to permit overflow of liquid from the sample test chamber to the overflow chamber and as a capillary lock to break connection between liquid in the sample test chamber and liquid in the overflow chamber and which prevents backflow of the liquid from the overflow chamber to the sample test chamber, and

means defining a sample application port for introduction of liquid into said capillary zone, said sample application port being in communication with said sample test chamber and contiguous to said overflow proportioning channel.

23. The device as set forth in claim 22, wherein said dimensions between about 0.007 and about 0.08 centimeter.

24. The device as set forth in claim 22, wherein the test chamber includes means defining an air relief vent opening.

25. The device as set forth in claim 22, further comprising an adhesive layer being formed on the underside of the top surface layer positioned in sealing relation to the spacer layer.

26. The device as set forth in claim 22, wherein the chambers are of substantially rectangular shape.

27. The device as set forth in claim 22, wherein the chambers are of a contoured configuration.

28. The device as set forth in claim 22, which additionally has present an absorbent wicking layer between the top and bottom layers.

29. The device as set forth in claim 22, wherein the interactive layer is a multiple reagent layer.

30. The device as set forth in claim 22, wherein the dimensions of the device are 3.7 cm long by 1 cm wide.

31. The device as set forth in claim 22, wherein the sample application port has a circular ring around it which rises above the surface of the port defining means.

32. The device as set forth in claim 22, wherein the thickness of the device is 0.05 to 0.3 cm.

33. The device as set forth in claim 22, wherein the surface of the top surface layer facing the capillary zone is coated with a surface active agent.

34. The device as set forth in claim 22, wherein the top surface layer is transparent.

35. The device as set forth in claim 22, wherein said spacer layer is a thermoplastic layer which bonds said top surface layer and interactive layer together.

36. A method for introducing a liquid into a test device comprising the steps of supplying a liquid to an application port of said test device which directs the fluid to a capillary channel that further directs said liquid into a reaction chamber containing interactive material capable of reacting with a component of said liquid to provide a detectable response, directing remaining fluid in excess of the volume of said reaction chamber into a second capillary channel arranged to direct said remaining liquid into an overflow chamber that functions to prevent said liquid back-flow from said overflow chamber into said reaction chamber, said capillary channels being sized to maintain a capillary flow of said liquid and said sample application port being in communication with said sample chamber and contiguous to said second capillary channel.