Capillary active test element having an intermediate layer situated between the support and the covering

• US 7,238,534 B1
• Filed: 12/03/1998
• Issued: 07/03/2007
• Est. Priority Date: 12/04/1997
• Status: Expired due to Fees

• Current Assignee: Roche Diagnostics GmbH (Roche Holding AG)
• Original Assignee: Roche Diagnostics GmbH (Roche Holding AG)
• Inventors: Zimmer, Volker
• Primary Examiner(s): ALEXANDER, LYLE
• Application Number:
  US09/554,793
• Time in Patent Office: 3,134 Days
• Field of Search: 436 9- 19, 436/63, 436 66- 69, 436/71, 436/74, 436/169, 436/178, 422 55- 61, 422/68.1, 422/73, 422/99, 422/100, 422/104, 204/403.03, 204/403.02, 204/400
• US Class Current: 436/169
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: G01N 2035/00108 Test strips, e.g. paper
• CPC Class Codes: G01N 33/54386 Analytical elements
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

The invention concerns a device for withdrawing samples of liquid samples for analytical elements. The capillary-device channel is essentially formed by a carrier, a cover and optionally an intermediate layer between the cover and carrier. A notch is located in one of the surfaces forming the channel capable of capillary liquid transport at the edge of the test element forming the sample application opening so that one side of the edge of the test element forming the sample application opening is at least partially discontinuous and the surface opposite to the notch is exposed. It also concerns a method for withdrawing a liquid sample into an analytical element with the aid of a device according to the invention.

Claims

1. A device for withdrawing samples of liquid samples for analytical elements, wherein the device comprises:

a carrier having a carrier surface defined by opposite carrier ends,

a detection element having opposite first and second ends, and

a cover having a surface defined by opposite first and second edges the surface facing the carrier and the second edge facing the first end of the detection element, the cover cooperating with the carrier surface and with the detection element to form a capillary-active channel, the channel having a sample application opening defined by at least one border positioned at one of the carrier ends, the channel extending at least from the opening to the second end of the detection element, such that the detection element is downstream of the opposite first and second edges of the cover and wherein at least one notch in the form of a partial groove and having a width less than that of the channel is positioned at the at least one border of the sample application opening of the channel so that one side of the border of the sample application opening is at least partially interrupted by the at least one notch and the surface facing the channel opposite to the at least one notch is exposed.

2. Device as claimed in claim 1, wherein at least two notches are located next to one another.

3. Device as claimed in claim 1, wherein the device includes at least two notches staggered on opposite sides of the border of the sample application opening.

4. Device as claimed in claim 1, further comprising a second cover and an intermediate layer positioned between the second cover and the carrier.

5. Device as claimed in claim 1, wherein at least one of the surfaces forming the inner surfaces of the channel is hydrophilized.

6. Device as claimed in claim 5, wherein the hydrophilization is achieved by a hydrophilic material.

7. Device as claimed in claim 5, wherein the hydrophilization is achieved by a hydrophilic layer.

8. Device as claimed in claim 7, wherein a layer of oxidized aluminium is used for the hydrophilization.

9. Device as claimed in claim 5, wherein the exposed surface opposite to the notch is hydrophilized.

10. Device as claimed in claim 9, wherein the hydrophilization is achieved by a hydrophilic material.

11. Device as claimed in claim 9, wherein the hydrophilization is achieved by a hydrophilic layer.

12. Device as claimed in claim 11, wherein a layer of oxidized aluminium is used for the hydrophilization.

13. A method for withdrawing a liquid sample into an analytical element, the method comprising the steps of providing a device that comprises a carrier having a carrier surface defined by opposite carrier ends, a detection element having opposite first and second ends, and a cover having a surface defined by opposite first and second edges, the surface facing the carrier and the second edge facing the first end of the detection element, the cover cooperating with the carrier surface and the detection element to form a capillary-active channel having a sample application opening defined by at least one border positioned at one of the carrier ends, the channel extending at least from the opening to the second end of the detection element such that the detection element is downstream of the opposite first and second edges of the cover, and wherein at least one notch in the form of a partial groove and having a width less than that of the channel is positioned at the at least one border of the sample application opening of the channel so that one side of the border of the sample application opening is at least partially interrupted by the at least one notch and the surface opposite to the at least one notch facing the channel is exposed and contacting the border of the sample application opening adjacent to the notch with the liquid sample so that the liquid sample is transported by capillary forces into the channel.

14. A device for withdrawing samples of liquid samples for analytical elements, wherein the device comprises:

a carrier having a carrier surface defined by opposite carrier ends,

a detection element having a reagent-impregnated membrane with opposite first and second ends, and

a cover having a surface defined by opposite first and second edges, the surface facing the carrier and the second edge facing the first end of the detection element, and the cover cooperating with the carrier surface and the detection element to form a capillary-active channel, the channel having a sample application opening defined by at least one border positioned at one of the carrier ends and extending at least from the opening to the second end of the membrane, such that the detection element is downstream of the opposite first and second edges of the cover, and

wherein at least one notch in the form of a partial groove is positioned at the at least one edge of the sample application opening of the channel so that one side of the border of the sample application opening is at least partially interrupted by the at least one notch and the surface facing the channel opposite to the at least one notch is exposed.

15. Device as claimed in claim 14, further comprising a second cover and an intermediate layer positioned between the second cover and the carrier.

16. Device as claimed in claim 14 wherein at least two notches are located next to one another.

17. Device as claimed in claim 14 wherein the device includes at least two notches staggered on opposite sides of the border of the sample application opening.

18. as claimed in 14 wherein at least one of the surfaces forming the inner surface of the channel is hydrophilized.

19. Device as claimed in claim 18 wherein the exposed surface opposite to the notch is hydrophilized.

20. Device as claimed in claim 18 wherein a layer of oxidized aluminium is used for the hydrophilization.

21. Device as claimed in claim 18 wherein the hydrophilization is achieved by a hydrophilic layer.

22. Device as claimed in claim 18 wherein the hydrophilization is achieved by a hydrophilic material.