Acetaminophen assay
AssigneeSekisui Diagnostics, LLC
InventorsRobert Acorn, Helen Cynthia Coady, Graham Coll
Life of this patent
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Abstract
Disclosed herein is an assay for determining the concentration of p-aminophenol present in a sample. More particularly, the present invention relates to an improvement of an enzyme-based assay for determining the concentration of acetaminophen present in a sample.
Claims41
A kit for determining the concentration of acetaminophen in a sample, the kit comprising:
- a first reagent (R1) comprising an aryl acylamidase for hydrolyzing acetaminophen to p-aminophenol;
- a second reagent (R2) comprising a xylenol chromophore for oxidative coupling to the p-aminophenol;
- and
- a suitable catalyst for catalyzing the oxidative coupling of the xylenol chromophore and the p-aminophenol
- wherein the xylenol chromophore is 2,5-dimethylphenol and the catalyst is hydrated MnCl2,
- wherein R2 comprises 2,5-dimethylphenol dissolved in DMSO,
- wherein the kit can detect 15.1 μg/mL acetaminophen in the presence of 1,000 mg/l of Intralipid®.
A method for determining the concentration of acetaminophen in an aqueous sample, the method comprising the steps of:
- hydrolyzing acetaminophen to form p-aminophenol;
- oxidatively coupling said p-aminophenol to a xylenol chromophore in the presence of a suitable catalyst to form a colored product;
- and
- determining the amount of said colored product formed, the amount of said colored product formed being proportional to the amount of acetaminophen present in said aqueous sample,
- wherein the method is reliable in the presence or absence of therapeutic levels of N-acetylcysteine (NAC) in said aqueous sample,
- wherein the xylenol chromophore is 2,5-dimethylphenol and the catalyst is hydrated MnCl2,
- and wherein R2 comprises 2,5-dimethylphenol pre-dissolved in DMSO.
An assay for determining the concentration of acetaminophen in an aqueous sample, the assay comprising the steps of
- contacting the aqueous sample with a first reagent (R1) comprising an aryl acylamidase enzyme and a suitable diluent to form a hydrolysis solution;
- optionally, diluting the hydrolysis solution;
- incubating the hydrolysis solution to permit a hydrolysis reaction wherein the acetaminophen is converted to p-aminophenol;
- contacting the hydrolysis solution with a second reagent (R2) comprising a xylenol chromophore where the xylenol chromophore is pre-dissolved in DMSO, to form an oxidative coupling solution;
- incubating the oxidative coupling solution to permit an oxidative coupling reaction wherein the xylenol chromophore is coupled to the p-aminophenol in the presence of a suitable catalyst to form a colored product;
- and
- determining the amount of the colored product formed, the amount of the colored product formed being proportional to the amount of acetaminophen present in the aqueous sample,
- wherein the assay is reliable in the presence or absence of therapeutic levels of N-acetylcysteine (NAC) in the aqueous sample.
A method for determining the concentration of p-aminophenol in an aqueous sample, the method comprising the steps of oxidatively coupling the p-aminophenol to a xylenol chromophore selected from the group consisting of 2,5-dimethylphenol, 2,6-dimethylphenol and 2,3-dimethylphenol, where the xylenol chromophore is pre-dissolved in DMSO, in the presence of a catalyst to form a colored product, the catalyst being a weak oxidizer;
- and determining the amount of the colored product formed, the amount of the colored product formed being proportional to the amount of p-aminophenol initially present in the aqueous sample.
Dependencies are inferred from the claim text.