Assay for bilirubin

Claim 3

The method of claim 1 wherein said interactive composition is admixed in a non-interfering liquid medium and is contacted together with said liquid sample in said reagent zone at a pH of from about 6.8 to about 9.5 and at a temperature of from about 15° to about 60° C.

Claim 4

The method of claim 1 wherein said interactive composition is present in an initially dry reagent zone.

Claim 5

The method of claim 1 wherein said interactive composition is present in an initially dry reagent zone which comprises said interactive composition distributed in a polymeric matrix and wherein said liquid sample is contacted together with said interactive composition in said reagent zone at a pH of from about 6.8 to about 9.5 and at a temperature of from about 15° to about 60° C.

Claim 6

The method of claim 1 wherein said detectable ligand is a colorimetrically detectable material having a molar extinction coefficient in excess of about 75,000.

Claim 7

The method of claim 1 wherein said detectable ligand is fluorimetrically detectable.

Claim 8

The method of claim 1 wherein said carrier of said bilirubin-active complex comprises a protein material.

Claim 9

The method of claim 1 wherein said carrier of said bilirubin-active complex comprises albumin, an albumin degradation product, or an albumin derivative.

Claim 10

The method of claim 1 wherein said liquid sample is a biological fluid.

Claim 11

The method of claim 1 wherein said liquid sample is blood serum.

Claim 12

The method of claim 1 wherein said liquid sample is blood serum which has been pretreated to reduce the amount of albumin contained therein.

Claim 13

The method of claim 1 wherein said detectable ligand is bromophenol blue or chlorophenol red.

Claim 14

The method of claim 1 wherein said detectable ligand is a member selected from the group consisting of an 8-anilino-1-naphthalenesulfonate salt, a 6-p-toluidino-2-naphthalene sulfonate salt, a 5-dimethylamino-1-naphthalene sulfonate salt, and a sulfonated methylated benzothiazole derivative.

Claim 15

The method of claim 1 wherein said detectable ligand is an 8-anilino-1-naphthalenesulfonate magnesium salt or the sulfonyl chloride derivative of a 6-p-toluidino-2-naphthalene-sulfonate salt.

Claim 16

An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone which comprises an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin.

Claim 17

An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone which comprises an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin.

Claim 18

An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone and an initially dry spreading zone in fluid contact with one another under conditions of use, said reagent zone comprising an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said spreading zone comprising a porous polymeric composition or particulate matter.

Claim 19

An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone and an initially dry spreading zone in fluid contact with one another under conditions of use, said reagent zone comprising an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said spreading zone comprising a porous polymeric composition or particulate matter.

Claim 20

An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone and an initially dry registration zone in fluid contact with one another under conditions of use, said reagent zone comprising an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said registration zone comprising material for receiving said diffusible ligand upon displacement thereof by bilirubin.

Claim 21

An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone and an initially dry registration zone in fluid contact with one another under conditions of use, said reagent zone comprising an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said registration zone comprising material for receiving said diffusible ligand upon displacement thereof by bilirubin.

Claim 22

An analytical element for the detection of bilirubin in an aqueous liquid sample, said element comprising a reagent layer superposed on a registration layer carried on a radiation-transmissive support, said reagent layer comprising an interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said registration layer comprising a material for receiving said diffusible ligand upon displacement thereof by bilirubin.

Claim 23

An analytical element for the detection of bilirubin in an aqueous liquid sample, said element comprising a reagent layer superposed on a registration layer carried on a radiation-transmissive support, said reagent layer comprising an interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said registration layer comprising a material for receiving said diffusible ligand upon displacement thereof by bilirubin.

Claim 24

The element of claim 18 wherein said reagent layer is an isotropically porous layer comprising said interactive composition and a porous polymeric composition or particulate matter.

Claim 25

The element of claim 18 wherein said element comprises an isotropically porous spreading layer superposed over said reagent layer and in fluid contact therewith under conditions of use, said spreading layer comprising a porous polymeric composition or particulate matter.

Claim 26

The element of claim 18 wherein said interactive composition comprises as the detectable ligand a colorimetrically detectable material having a molar extinction coefficient in excess of about 75,000, and wherein said element comprises a radiation-blocking layer interposed between said reagent layer and said registration layer.

Claim 27

The element of claim 18 wherein said bilirubin-active complex comprises as the detectable ligand a fluorimetrically detectable material.

Claim 28

The element of claim 18 wherein said carrier of said bilirubin-active complex comprises a protein material.

Claim 29

The element of claim 18 wherein said carrier of said bilirubin-active complex comprises albumin, an albumin degradation product, or an albumin derivative.

Claim 30

The element of claim 18 wherein said bilirubin-active complex comprises as the detectable ligand bromophenol blue or chlorophenol red.

Claim 31

The element of claim 18 wherein the bilirubin-active complex comprises as the detectable ligand a member selected from the group consisting of an 8-anilino-1-naphthalene-sulfonate salt, a 6-p-toluidino-2-naphthalene sulfonate salt, a 5-dimethylamino-1-naphthalene sulfonate salt, and a sulfonated methylated benzothiazole derivative.

Claim 32

The element of claim 18 wherein the bilirubin-active complex comprises as detectable ligand an 8-anilino-1-naphthalenesulfonate magnesium salt or the sulfonyl chloride derivative of a 6-p-toluidino-2-naphthalene-sulfonate salt.

Claim 33

An essentially dry multilayer analytical element for the detection of bilirubin in an aqueous liquid sample, said element comprising an isotropically porous spreading layer superposed over a reagent layer which, in turn, is superposed over a registration layer carried on a radiation-transmissive support, each of said layers in fluid contact with one another under conditions of use, said spreading layer comprising a porous polymeric composition or particulate matter and an amount of surfactant effective to normalize transport of bilirubin therethrough, said reagent layer comprising an interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said registration layer comprising a material for receiving said diffusible ligand upon displacement thereof by bilirubin.

Claim 34

An essentially dry multilayer analytical element for the detection of bilirubin in an aqueous liquid sample, said element comprising an isotropically porous spreading layer superposed over a reagent layer which, in turn, is superposed over a registration layer carried on a radiation-transmissive support, each of said layers in fluid contact with one another under conditions of use, said spreading layer comprising a porous polymeric composition or particulate matter and an amount of surfactant effective to normalize transport of bilirubin therethrough, said reagent layer comprising an interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10 7 and a first order binding constant to said detectable ligand which is in excess of 10 5 but less than the aforementioned binding constant to bilirubin, and said registration layer comprising a material for receiving said diffusible ligand upon displacement thereof by bilirubin.

Claim 35

The element of claim 28 wherein said reagent layer is substantially impermeable to materials having a molecular weight equal to or greater than that of albumin.

Claim 36

The element of claim 28 wherein said element comprises a radiation-blocking layer interposed between said reagent layer and said registration layer.

Claim 37

The element of claim 28 wherein said bilirubin-active complex comprises as the detectable ligand a fluorimetrically detectable material.

Claim 38

The element of claim 28 wherein the bilirubin-active complex comprises as the detectable ligand a member selected from the group consisting of an 8-anilino-1-naphthalene-sulfonate salt, a 6-p-toluidino-2-naphthalene sulfonate salt, a 5-dimethylamino-1-naphthalene sulfonate salt, and a sulfonated methylated benzothiazole derivative.

Claim 39

The element of claim 28 wherein the bilirubin-active complex comprises as detectable ligand an 8-anilino-1-naphthalenesulfonate magnesium salt or the sulfonyl chloride derivative of a 6-p-toluidino-2-naphthalene-sulfonate salt.