Support membrane

• US 5,494,638 A
• Filed: 09/23/1994
• Issued: 02/27/1996
• Est. Priority Date: 06/19/1991
• Status: Expired due to Term

• Current Assignee: Hypoguard USA Inc. (ARKRAY, Inc)
• Original Assignee: Hypoguard UK Ltd (ARKRAY, Inc)
• Inventors: Gullick, Stephen P.
• Primary Examiner(s): ALEXANDER, LYLE
• Application Number:
  US08/311,713
• Time in Patent Office: 522 Days
• Field of Search: 422/56-58, 422/61, 435/805, 436/170
• US Class Current: 422/408
• CPC Class Codes: G01N 33/521 Single-layer analytical elements
• CPC Class Codes: G01N 33/545 Synthetic resin
• CPC Class Codes: Y10S 435/805 Test papers

Abstract

The present invention relates to a membrane suitable for use as the support for one or more test reagents for testing a material applied to the membrane, which membrane is characterized in that it is initially an open pored porous material and in that at least part of the length the pores therein are blinded so that cell wall fragments from the material applied to the membrane are substantially prevented from passage through the membrane. Preferably, the pores are totally blinded by a gelatin matix containing one or more reagents which react with a fluid applied to one surface of the membrane to give a color which can be observed from a second surface of the membrane.

Claims

1. A membrane suitable for use as a support for at least one test reagent for testing a fluid material containing cellular components which is to be applied to the membrane, which membrane is initially an open pored porous material and consists essentially of bores at least some of which have had at least part of their length blinded with a pore blinding material which is in a form selected from the group consisting of a solid, a gel and a matrix which substantially fills the transverse cross-section of said pores, whereby the said cellular components and fragments thereof in the material applied to the membrane are substantially prevented from entering the pores of the membrane and essentially no cell wall rupture occurs thereby reducing red coloration due to blood cell fragments.

2. A membrane as claimed in claim 1, wherein said transverse cross-section of the pores of the membrane are substantially completely filled for substantially all of their axial length with the blinding material.

3. A membrane as claimed in claim 1, wherein the bores of the pores of the membrane are blinded by a material containing at least one reagent which responds to a component in the material to be tested.

4. A membrane as claimed in claim 1, wherein the blinding material is a gelatin.

5. A membrane as claimed in claim 1, wherein the membrane is a polysulphone resin.

6. A fluid testing device incorporating a membrane as claimed in claim 1.

7. A device as claimed in claim 6, wherein the device comprises a sample retaining chamber for containing a sample of the fluid to be tested, said chamber having a wall thereof formed at least in part by said membrane which is to be contacted by a sample introduced into said chamber.