Fluid conducting test strip with transport medium

Claim 2

A reagent strip for measuring the concentration of an analyte in a test sample, suitable for evaluation by the human eye or by mechanical viewing means, consisting essentially of: a testing pad formed from an anisotropic membrane impregnated with a color-forming reagent system specific to an analyte and having a side with relatively small pores which defines a testing surface and an opposite side with relatively large pores which defines a sample receiving surface; and a porous sample transport medium attached to the sample receiving surface of the testing pad, said transport medium being capable of accepting a whole blood sample on a sample accepting surface and transporting a detectable portion of the sample to the sample receiving surface.

Claim 3

The reagent strip of claim 1 wherein the sample accepting surface of the transport medium is coated with a film containing a hydrophobic polymer.

Claim 4

The reagent strip of claim 1 wherein the transport medium is capable of holding about 35 microliters of blood and of passing about 3 microliters of blood to said testing pad.

Claim 5

The reagent strip of claim 1 wherein the transport medium has pores which are in the size range of about 20 to about 200 micrometers.

Claim 6

The reagent strip of claim 1 wherein the transport medium is composed of polyethylene.

Claim 7

The reagent strip of claim 1 wherein the testing pad has pores in the size range of about 5 to about 50 micrometers on the side with relatively large pores decreasing to about 0.1 to about 1.0 micrometer on the side with relatively small pores.

Claim 8

The reagent strip of claim 1 wherein the testing pad is composed of polysulfone.

Claim 9

The reagent strip of claim 1 wherein an adhesive layer formed along an outer edge of the testing pad is attached to the testing pad and the transport medium.

Claim 10

The reagent strip of claim 1 wherein a discontinuous adhesive layer is positioned between and attached to the testing pad and the transport medium.

Claim 11

The reagent strip of claim 1 which further comprises a rigid support member defining an aperture therethrough and having a free surface adapted to contact and engage mechanical viewing means.

Claim 12

The reagent strip of claim 10 wherein the transport medium includes a region that does not contact the testing pad.

Claim 13

A reagent strip for measuring the concentration of an analyte in a test sample suitable for evaluation primarily by mechanical viewing means, consisting essentially of: a rigid support member defining an aperture therethrough and having a surface adapted to contact and engage viewing means and a portion disposed about the aperture with a predetermined thickness; a testing pad formed from an anisotropic membrane impregnated with a color-forming reagent system specific to an analyte and having a side with relatively small pores which defines a testing surface and an opposite side with relatively large pores which defines a sample receiving surface, said testing surface being attached to said support member so that the testing surface faces and overlaps the aperture; and a porous sample transport medium attached to the sample receiving surface of the testing pad, said transport medium being capable of accepting a whole blood sample and transporting a detectable portion of the sample to the sample receiving surface; whereby the testing surface is maintained at an optimum viewing distance relative to said viewing means when the free surface of the support member engages said viewing means.

Claim 14

A reagent strip for measuring the concentration of an analyte in a test sample suitable for evaluation primarily by mechanical viewing means, consisting essentially of: a rigid support member defining an aperture therethrough and having a surface adapted to contact and engage viewing means and a portion disposed about the aperture with a predetermined thickness; a testing pad formed from an anisotropic membrane impregnated with a color-forming reagent system specific to an analyte and having a side with relatively small pores which defines a testing surface and an opposite side with relatively large pores which defines a sample receiving surface, said testing surface being attached to said support member so that the testing surface faces and overlaps the aperture; and a porous sample transport medium attached to the sample receiving surface of the testing pad, said transport medium being capable of accepting a whole blood sample and transporting a detectable portion of the sample to the sample receiving surface; whereby the testing surface is maintained at an optimum viewing distance relative to said viewing means when the free surface of the support member engages said viewing means.

Claim 15

The reagent strip of claim 12 wherein the portion of the support member disposed about the aperture has a thickness in the range of about 0.002 to about 0.050 of an inch.

Claim 16

The reagent strip of claim 12 wherein the transport medium is capable of holding about 35 microliters of blood and of passing about 3 microliters of blood to said testing pad.

Claim 17

The reagent strip of claim 12 wherein the transport medium has pores which are in the size range of about 20 to about 200 micrometers.

Claim 18

The reagent strip of claim 12 wherein the transport medium is composed of polyethylene.

Claim 19

The reagent strip of claim 12 wherein the testing pad has pores in the size range of about 5 to about 50 micrometers on the side with relatively large pores decreasing to about 0.1 to about 1.0 micrometer on the side with relatively small pores.

Claim 20

The reagent strip of claim 12 wherein the testing pad is composed of polysulfone.

Claim 21

The reagent strip of claim 12 wherein an adhesive layer formed along an outer edge of the testing pad is attached to the testing pad and the transport medium.

Claim 22

The reagent strip of claim 12 wherein a discontinuous adhesive layer is positioned between and attached to the testing pad and the transport medium.

Claim 25

The method of claim 21 in which the coloration of the testing surface is compared to a calibrated color standard to determine the concentration of the analyte in the test sample.

Claim 26

The method of claim 21 which further comprises locating the testing surface a reproducible distance from a viewing means by contacting the viewing means with a rigid support member which has a controlled thickness, defines an aperture, and abuts the testing surface.

Claim 27

A reagent strip for measuring the concentration of an analyte in a liquid sample which exhibits an optically visible color change as a function of the concentration of said analyte in said sample, consisting essentially of: a relatively rigid support member having opposed first and second major surfaces and having an aperture therethrough; a testing pad overlying said aperture on said first major surface, said testing pad having a sample receiving surface and an opposed testing surface, with said testing surface in face-to-face relationship with said first major surface of said support and with a portion of said testing surface being optically visible through said aperture; said testing pad formed from a porous anisotropic membrane, said pores decreasing in effective diameter from said sample receiving surface to said testing surface; said testing pad impregnated with reactants selected to react with said analyte if present in said testing pad to produce a color change visible at said testing surface; a porous sample transport medium overlying said sample receiving surface of said testing pad and having portions extending beyond the perimeter of said testing pad to overlie, in face-to-face contact, the first surface of said support member; whereby said liquid sample may be applied to said transport medium, a portion of said sample may be transported to the sample receiving surface of said testing pad and a portion of said sample may be transported through said testing pad, wherein analyte if present will react with said reactants in said testing pad and any resulting color change will be visible on the testing surface through said aperture, and whereby said portion of the transport medium extending beyond the perimeter of the testing pad provides a reservoir for excess liquid sample applied to the transport surface.

Claim 28

A reagent strip for measuring the concentration of an analyte in a liquid sample which exhibits an optically visible color change as a function of the concentration of said analyte in said sample, consisting essentially of: a relatively rigid support member having opposed first and second major surfaces and having an aperture therethrough; a testing pad overlying said aperture on said first major surface, said testing pad having a sample receiving surface and an opposed testing surface, with said testing surface in face-to-face relationship with said first major surface of said support and with a portion of said testing surface being optically visible through said aperture; said testing pad formed from a porous anisotropic membrane, said pores decreasing in effective diameter from said sample receiving surface to said testing surface; said testing pad impregnated with reactants selected to react with said analyte if present in said testing pad to produce a color change visible at said testing surface; a porous sample transport medium overlying said sample receiving surface of said testing pad and having portions extending beyond the perimeter of said testing pad to overlie, in face-to-face contact, the first surface of said support member; whereby said liquid sample may be applied to said transport medium, a portion of said sample may be transported to the sample receiving surface of said testing pad and a portion of said sample may be transported through said testing pad, wherein analyte if present will react with said reactants in said testing pad and any resulting color change will be visible on the testing surface through said aperture, and whereby said portion of the transport medium extending beyond the perimeter of the testing pad provides a reservoir for excess liquid sample applied to the transport surface.

Claim 29

The test pad of claim 24 wherein the transport medium comprises essentially incompressible material to ameliorate the unintended expulsion of applied liquid sample.

Claim 30

The test pad of claim 25 wherein the outer surface of said transport medium is hydrophobic with respect to the remainder of the transport medium.