Diagnostics based on tetrazolium compounds
AssigneeLifeScan, Inc.
InventorsTianmei Ouyang, Yeung Siu Yu
Life of this patent
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Abstract
A reagent is suitable for measuring the concentration of an analyte in a hemoglobin-containing biological fluid, such as whole blood. The reagent comprises a flavin-dependent enzyme that has specificity for the analyte, a flavin cofactor if, and only if, a flavin is not bound to the enzyme, a tetrazolium dye precursor, an electron transfer agent, and a nitrite salt. The reagent causes dye formation that is a measure of the analyte concentration. The nitrite salt suppresses interfering dye formation caused non-enzymatically by the hemoglobin. Preferably, the reagent is used in a dry strip for measuring glucose in whole blood.
Claims13
A dry reagent strip for measuring a concentration of an analyte in a hemoglobin-containing biological fluid comprising a support layer on which is a test pad having a coating of a reagent comprising:
- a) a flavin-dependent enzyme that has a flavin bound to it and that has specificity for the analyte,
- b) a tetrazolium dye precurser,
- c) an electron transfer agent, and
- d) a nitrite salt.
A dry reagent strip for measuring a concentration of an analyte in a hemoglobin-containing biological fluid comprising a support layer on which is a test pad having a coating of a reagent comprising:
- a) a flavin-dependent enzyme that has a flavin bound to it and that has specificity for the analyte,
- b) flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD),
- c) a tetrazolium dye precurser,
- d) an electron transfer agent, and
- e) a nitrite salt.
A dry reagent strip for measuring a concentration of an analyte in a hemoglobin-containing biological fluid comprising a support layer on which is a test pad and a top layer overlaying the test pad in which the test pad is coated in a reagent comprising:
- a) a flavin-dependent enzyme that has a flavin bound to it and that has specificity for the analyte,
- b) a tetrazolium dye precurser, and
- c) an electron transfer agent;
- and the support layer and/or the top layer is coated with a nitrite salt.
A dry reagent strip for measuring a concentration of an analyte in a hemoglobin-containing biological fluid comprising a support layer on which is a test pad and a top layer overlaying the test pad in which the test pad is coated in a reagent comprising:
- a) a flavin-dependent enzyme that has a flavin bound to it and that has specificity for the analyte,
- b) flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD),
- c) a tetrazolium dye precurser, and
- d) an electron transfer agent;
- and the support layer and/or the top layer is coated with a nitrite salt.
A dry reagent test strip for measuring a concentration of glucose in a hemoglobin-containing biological fluid, comprising:
- a) a support layer
- b) on the support layer, a test pad having a coating that comprises
- i) glucose oxidase that has a flavin bound to it,
- ii) a tetrazolium dye precurser, and
- iii) phenazine methosulfate (PMS) or an analog thereof, and
- c) on the test pad, a bilubous top layer that is coated with a nitrite salt.
A dry reagent test strip for measuring a concentration of glucose in a hemoglobin-containing biological fluid, comprising
- a) a support layer
- b) on the support layer, a test pad having a coating that comprises:
- a. a flavin-dependent enzyme that does not have a flavin bound to it,
- b. flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD),
- c. a tetrazolium dye precurser, and
- d. phenazine methosulfate (PMS) or an analog thereof, and
- c) on the test pad, a bilubous top layer that is coated with a nitrite salt.
Dependencies are inferred from the claim text.