Catalytic test composition intended to produce a range of colors

Claim 2

A test composition for the visual determination of an analyte in a fluid sample, comprising: (a) a catalytic system capable of generating reduced nicotinamide adenine dinucleotide by reaction with an analyte in a fluid sample; (b) a first catalytic system capable of generating a reduced first indicator by reaction with reduced nicotinamide adenine dinucleotide; and (c) a second catalytic system capable of generating a change in hue in a second indicator component by reaction with reduced nicotinamide adenine dinucleotide, which second catalytic system includes: (i) a disulfide reductase; (ii) a disulfide substrate; and (iii) a thiol indicator; wherein the disulphide reductase is capable of catalyzing the reaction between reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which can interact with the thiol indicator to produce a change in hue of the second indicator; whereby the generation of reduced first indicator and the changed hue of the second indicator occur substantially simultaneously to provide a range of hues, the particular final hue produced by the test composition depending on concentration of the analyte.

Claim 3

The test composition of claim 1 in which the first or second catalytic system is capable of producing a reduced third indicator.

Claim 4

The test composition of claim 2 in which one indicator component reduction produces a change from a hue to colorless.

Claim 5

The test composition of claim 1 which additionally includes a color retardant.

Claim 6

The test composition of claim 1 in which the generation of the final hue of the test composition is essentially complete in less than about ten minutes.

Claim 7

The test composition of claim 1 in which the hue of the second indicator is changed to yellow.

Claim 8

The test composition of claim 1 in which the thiol indicator is a disulfide.

Claim 9

The test composition of claim 7 in which the thiol indicator is an analog of 5,5'-dithiobis-(2-nitrobenzoic acid).

Claim 10

The test composition of claim 1 in which the reduced nicotinamide adenine dinucleotide is a reduced phosphorylated nicotinamide adenine dinucleotide.

Claim 11

The test composition of claim 1 which additionally includes a buffer which maintains the pH in the range of about 6 to 8.

Claim 12

The test composition of claim 1 in which the analyte is cholesterol.

Claim 13

The test composition of claim 1 in which the analyte is alcohol.

Claim 14

A test composition for the visual determination of glucose in an aqueous fluid sample, comprising: (a) a catalytic system capable of generating reduced nicotinamide adenine dinucleotide by reaction with glucose; (b) a first catalytic system composed of a catalyst having diaphorase activity, an oxidized first indicator and an oxidized third indicator each capable of reacting with reduced nicotinamide adenine dinucleotide in the presence of the catalyst to produce a reduced first and third indicator; and (c) a second catalytic system composed of a disulfide reductase, a disulfide substrate and a thiol indicator, wherein the disulfide reductase is capable of catalyzing the reaction between reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which reduces the thiol indicator to produce a reduced second indicator; whereby the generation of the reduced first and second indicators occurs substantially simultaneously to provide a range of hues, the final hue produced by the test composition depending on the concentration of glucose in the sample.

Claim 15

A test composition for the visual determination of glucose in an aqueous fluid sample, comprising: (a) a catalytic system capable of generating reduced nicotinamide adenine dinucleotide by reaction with glucose; (b) a first catalytic system composed of a catalyst having diaphorase activity, an oxidized first indicator and an oxidized third indicator each capable of reacting with reduced nicotinamide adenine dinucleotide in the presence of the catalyst to produce a reduced first and third indicator; and (c) a second catalytic system composed of a disulfide reductase, a disulfide substrate and a thiol indicator, wherein the disulfide reductase is capable of catalyzing the reaction between reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which reduces the thiol indicator to produce a reduced second indicator; whereby the generation of the reduced first and second indicators occurs substantially simultaneously to provide a range of hues, the final hue produced by the test composition depending on the concentration of glucose in the sample.

Claim 16

The test composition of claim 13 in which the reduction of at least one of the first, third or thiol indicator produces a change from a hue to colorless.

Claim 17

The test composition of claim 14 in which the generation of the final hue of the test composition is essentially complete in less than about ten minutes.

Claim 18

A test device for the visual determination of an analyte in a fluid sample, comprising: (a) a carrier matrix; and (b) a test composition incorporated therewith, the test composition including: a catalytic system capable of generating reduced nicotinamide adenine dinucleotide by a reaction with an analyte; a first catalytic system capable of generating a reduced first indicator by reaction with reduced nicotinamide adenine dinucleotide; and a second catalytic system capable of generating a yellow second indicator by reaction with reduced nicotinamide adenine dinucleotide, which second catalytic system includes (i) a disulfide reductase; (ii) a disulfide substrate; and (iii) a thiol indicator; wherein the disulfide reductase is capable of catalyzing the reaction between reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which can interact with the thiol indicator to produce a yellow second indicator; whereby the generation of the reduced first indicator and yellow second indicator occurs substantially simultaneously to provide a range of hues, the particular final hue produced by the test composition depending on the concentration of the analyte in a fluid sample.

Claim 19

A test device for the visual determination of an analyte in a fluid sample, comprising: (a) a carrier matrix; and (b) a test composition incorporated therewith, the test composition including: a catalytic system capable of generating reduced nicotinamide adenine dinucleotide by a reaction with an analyte; a first catalytic system capable of generating a reduced first indicator by reaction with reduced nicotinamide adenine dinucleotide; and a second catalytic system capable of generating a yellow second indicator by reaction with reduced nicotinamide adenine dinucleotide, which second catalytic system includes (i) a disulfide reductase; (ii) a disulfide substrate; and (iii) a thiol indicator; wherein the disulfide reductase is capable of catalyzing the reaction between reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which can interact with the thiol indicator to produce a yellow second indicator; whereby the generation of the reduced first indicator and yellow second indicator occurs substantially simultaneously to provide a range of hues, the particular final hue produced by the test composition depending on the concentration of the analyte in a fluid sample.

Claim 20

The test device of claim 16 in which the first or second catalytic system is capable of producing a reduced third indicator.

Claim 21

The test device of claim 17 in which at least one of the first or third indicators changes from a hue to colorless.

Claim 22

The test device of claim 18 in which at least one of the first or third indicators is compartmentalized within the carrier matrix.

Claim 23

A multilayer test device for the visual determination of glucose in a body fluid sample, (a) an inert support member, and in laminar relationship thereto; (b) at least two layers, each composed of a hydrophilic carrier, one layer containing one of a first or third oxidized indicator component and the second layer containing (i) nicotinamide adenine dinucleotide, (ii) a glucose dehydrogenase capable of generating reduced nicotinamide adenine dinucleotide by reaction with glucose, (iii) a disulfide substrate, (iv) the other of the oxidized first indicator or the oxidized third indicator, (v) a catalyst having diaphorase activity capable of facilitating the reaction between the reduced form of nicotinamide adenine dinucleotide and the oxidized first and third indicators to produce reduced first and third indicators, (vi) a disulfide reductase; and (vii) a thiol indicator; wherein the disulfide reductase is capable of catalyzing the reaction between the generated reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which can reduce the thiol indicator; whereby the device is capable of generating substantially simultaneously a range of hues, the particular final hue produced in the test device depending on the concentration of glucose in the sample.

Claim 24

A multilayer test device for the visual determination of glucose in a body fluid sample, (a) an inert support member, and in laminar relationship thereto; (b) at least two layers, each composed of a hydrophilic carrier, one layer containing one of a first or third oxidized indicator component and the second layer containing (i) nicotinamide adenine dinucleotide, (ii) a glucose dehydrogenase capable of generating reduced nicotinamide adenine dinucleotide by reaction with glucose, (iii) a disulfide substrate, (iv) the other of the oxidized first indicator or the oxidized third indicator, (v) a catalyst having diaphorase activity capable of facilitating the reaction between the reduced form of nicotinamide adenine dinucleotide and the oxidized first and third indicators to produce reduced first and third indicators, (vi) a disulfide reductase; and (vii) a thiol indicator; wherein the disulfide reductase is capable of catalyzing the reaction between the generated reduced nicotinamide adenine dinucleotide and the disulfide substrate to produce a reaction product which can reduce the thiol indicator; whereby the device is capable of generating substantially simultaneously a range of hues, the particular final hue produced in the test device depending on the concentration of glucose in the sample.

Claim 25

The multilayer test device of claim 20 in which the hydrophilic carrier is gelatin and each layer is affixed by coating.

Claim 26

The multilayer test device of claim 21 in which the thiol indicator is a water soluble disulfide.

Claim 27

The multilayer test device of claim 24 in which the reduction of the water soluble disulfide produces a yellow hue.

Claim 28

The test device of claim 23 in which the water soluble disulfide is a water soluble analogue of 5,5'-dithiobis-(2-nitrobenzoic acid).

Claim 29

The multilayer test device of claim 20 in which the one layer additionally includes a color retardant.

Claim 30

The multilayer test device of claim 25 in which the color retardant is chosen from potassium ferricyanide or 1-N-ethyl-4-methylquinolinium iodide.