Oxidative coupling dye for spectrophotometric quantitive analysis of analytes

Claim 1

A test device containing a reaction pad to which a fluid to be analyzed is to be applied, said reaction pad including a hydrophilic matrix pad supported on a substrate holder, said reaction pad having pores containing a reagent system comprising an oxidase enzyme, a peroxidase, and a dye indicator comprising 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-1-naphthalene sulfonate.

Claim 7

A method of determining analyte concentration in a liquid which comprises: (a) quantitatively measuring baseline reflectance from a first surface of a reagent element comprising an inert, porous, hydrophilic, substantially reflective, single-layer matrix having pores of a size sufficient to exclude red blood cells and a reagent system which interact with said analyte to produce a light-absorbing reaction product, said reagent system being impregnated in the pores of said matrix, prior to application of said liquid to said reagent element; (b) applying said liquid to a second surface of said reagent element and allowing said liquid to migrate from said second surface to said first surface; (c) quantitatively measuring reaction reflectance from said first surface of said reagent element without removing excess sample or non-migrating components of said sample from said second surface; (d) quantitatively measuring reflectance of interfering substances from said first surface of said reagent element using a wavelength of light reflected by interfering substances and different from the wavelength of light used to measure said reaction product reflectance in order to correct for background reflectance at the reaction product wavelength caused by interfering substances; and (e) calculating a value expressing said analyte concentration from said reflectance measurements, wherein said reaction system includes a dye couple consisting essentially of 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-l-naphthalene sulfonate and at least one reagent capable of reacting with said analyte to produce a strong oxidizing agent which reacts with said dye couple to form a blue dye.

Claim 8

A method of determining analyte concentration in a liquid which comprises: (a) quantitatively measuring baseline reflectance from a first surface of a reagent element comprising an inert, porous, hydrophilic, substantially reflective, single-layer matrix having pores of a size sufficient to exclude red blood cells and a reagent system which interact with said analyte to produce a light-absorbing reaction product, said reagent system being impregnated in the pores of said matrix, prior to application of said liquid to said reagent element; (b) applying said liquid to a second surface of said reagent element and allowing said liquid to migrate from said second surface to said first surface; (c) quantitatively measuring reaction reflectance from said first surface of said reagent element without removing excess sample or non-migrating components of said sample from said second surface; (d) quantitatively measuring reflectance of interfering substances from said first surface of said reagent element using a wavelength of light reflected by interfering substances and different from the wavelength of light used to measure said reaction product reflectance in order to correct for background reflectance at the reaction product wavelength caused by interfering substances; and (e) calculating a value expressing said analyte concentration from said reflectance measurements, wherein said reaction system includes a dye couple consisting essentially of 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-l-naphthalene sulfonate and at least one reagent capable of reacting with said analyte to produce a strong oxidizing agent which reacts with said dye couple to form a blue dye.

Claim 12

A method of determining analyte concentration in a liquid which comprises: (a) quantitatively measuring baseline reflectance from a first surface of a reagent element comprising an inert, porous, hydrophilic, substantially reflective, single-layer matrix having pores of a size sufficient to exclude red blood cells and a reagent system which interact with said analyte to produce a light-absorbing reaction product, said reagent system being impregnated in the pores of said matrix, prior to application of said liquid to said reagent element; (b) applying said liquid to a second surface of said reagent element and allowing said liquid to migrate from said second surface to said first surface; (c) quantitatively measuring reaction reflectance from said first surface of said reagent element without removing excess sample or non-migrating components of said sample from said second surface; (d) quantitatively measuring reflectance of interfering substances from said first surface of said reagent element using a wavelength of light reflected by interfering substances and different from the wavelength of light used to measure said reaction product reflectance in order to correct for background reflectance at the reaction product wavelength caused by interfering substances; and (e) calculating a value expressing said analyte concentration from said reflectance measurements, wherein said analyte comprises a substance that reacts with an enzyme to produce hydrogen peroxide and said reagent system comprises said enzyme, peroxidase and 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-1-naphthalene sulfonate.

Claim 13

A method of determining analyte concentration in a liquid which comprises: (a) quantitatively measuring baseline reflectance from a first surface of a reagent element comprising an inert, porous, hydrophilic, substantially reflective, single-layer matrix having pores of a size sufficient to exclude red blood cells and a reagent system which interact with said analyte to produce a light-absorbing reaction product, said reagent system being impregnated in the pores of said matrix, prior to application of said liquid to said reagent element; (b) applying said liquid to a second surface of said reagent element and allowing said liquid to migrate from said second surface to said first surface; (c) quantitatively measuring reaction reflectance from said first surface of said reagent element without removing excess sample or non-migrating components of said sample from said second surface; (d) quantitatively measuring reflectance of interfering substances from said first surface of said reagent element using a wavelength of light reflected by interfering substances and different from the wavelength of light used to measure said reaction product reflectance in order to correct for background reflectance at the reaction product wavelength caused by interfering substances; and (e) calculating a value expressing said analyte concentration from said reflectance measurements, wherein said analyte comprises a substance that reacts with an enzyme to produce hydrogen peroxide and said reagent system comprises said enzyme, peroxidase and 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-1-naphthalene sulfonate.

Claim 18

A method for determining glucose comprising the steps of: (a) applying a whole blood sample to an application site on a reagent element wherein said reagent element comprises a single-layer, substantially reflective, porous, hydrophilic matrix which filters out red blood cells and to which is bound a signal-producing system comprising glucose oxidase, peroxidase, and a dye indicator, which signal-producing system reacts with glucose to form a reaction dye product; (b) allowing the sample to migrate to a reading site on said membrane different from said application site; (c) monitoring reflectance at said reading site for a decrease in reflectance indicative of sample presence in said reading site in order to initiate timing of an incubation period; and (d) determining the change in reflectance at said reading site during the incubation period as a measure of dye product formed to determine the amount of glucose in said sample, in which all reflectance measurements at said reading site are performed without removing excess sample or red blood cells from said application site and at least one measurement is taken at a wavelength at which light is absorbed by said dye product, wherein said dye indicator comprises 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-1-naphthalene sulfonate.

Claim 19

A method for determining glucose comprising the steps of: (a) applying a whole blood sample to an application site on a reagent element wherein said reagent element comprises a single-layer, substantially reflective, porous, hydrophilic matrix which filters out red blood cells and to which is bound a signal-producing system comprising glucose oxidase, peroxidase, and a dye indicator, which signal-producing system reacts with glucose to form a reaction dye product; (b) allowing the sample to migrate to a reading site on said membrane different from said application site; (c) monitoring reflectance at said reading site for a decrease in reflectance indicative of sample presence in said reading site in order to initiate timing of an incubation period; and (d) determining the change in reflectance at said reading site during the incubation period as a measure of dye product formed to determine the amount of glucose in said sample, in which all reflectance measurements at said reading site are performed without removing excess sample or red blood cells from said application site and at least one measurement is taken at a wavelength at which light is absorbed by said dye product, wherein said dye indicator comprises 3-methyl-2-benzothiazolinone hydrazone and 8-anilino-1-naphthalene sulfonate.