Patent US4404286A successfully refreshed from Google Patents.
US4404286A
Expired / Lapsed
US
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Bilirubin assay
Assignee: Dow Chemical Co
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Filing: 1982-02-22
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Granted: 1983-09-13
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Expires: 2002-02-22
Abstract
Abstract An improved reagent and method for assay of total bilirubin in biological fluids utilizes diazo sulfanilic acid to convert bilirubin to azobilirubin which is then quantitatively measured. The improved reagent and method include the solvent accelerator tetramethylene sulfone. The use of tetramethylene sulfone as also allows the use of nonionic surfactants, obviating the need for serum blank correction in highly lipemic serum. Furthermore, the use of tetramethylene sulfone and nonionic surfactants renders the reagent mixture less viscous facilitating automated analysis.
Inventors
- 👤 Bruce C. Shull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:53
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/72; G01N33/728; Y; Y10; Y10S; Y10S436/00; Y10S436/903; Y10T; Y10T436/00; Y10T436/14; Y10T436/145555; Y10T436/146666; Y10T436/25; Y10T436/25125
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
33 words
A method for the assay of total bilirubin which comprises incubating a mixture of bilirubin containing biological fluid, diazo sulfanilic acid, tetramethylene sulfone and a nonionic surfactant, and subsequently measuring the color produced.
Claim 2
Independent Claim
33 words
A method for the assay of total bilirubin which comprises incubating a mixture of bilirubin containing biological fluid, diazo sulfanilic acid, tetramethylene sulfone and a nonionic surfactant, and subsequently measuring the color produced.
Claim 3
Dependent Claim
15 words
A method of claim 1 wherein the bilirubin containing biological fluid is human blood serum.
Claim 4
Dependent Claim
40 words
A method of claim 1 wherein the nonionic surfactant is an ethoxylated alkyl phenol of the formula C 9 H 19 C 6 H 4 (OCH 2 CH 2 ) n OH wherein n has an average value of 4.
Claim 5
Dependent Claim
37 words
In a reagent composition for the assay of total bilirubin in a bilirubin containing biological fluid which comprises diazo sulfanilic acid, the improvement wherein the reagent also comprises the solvent accelerator tetramethylene sulfone and a nonionic surfactant.
Claim 6
Dependent Claim
37 words
In a reagent composition for the assay of total bilirubin in a bilirubin containing biological fluid which comprises diazo sulfanilic acid, the improvement wherein the reagent also comprises the solvent accelerator tetramethylene sulfone and a nonionic surfactant.
Claim 7
Dependent Claim
41 words
The improved composition of claim 4 wherein the nonionic surfactant is an ethoxylated alkyl phenol of the formula C 9 H 19 C 6 H 4 (OCH 2 CH 2 ) n OH wherein n has an average value of 4.
Claim 8
Dependent Claim
43 words
A kit for total bilirubin assay which comprises (a) a bilirubin reagent comprising sulfanilic acid, a mineral acid and tetramethylene sulfone; (b) a surfactant reagent comprising a nonionic surfactant and a solvent; and (c) a nitrite reagent comprising a source of nitrite ion.
Claim 9
Dependent Claim
43 words
A kit for total bilirubin assay which comprises (a) a bilirubin reagent comprising sulfanilic acid, a mineral acid and tetramethylene sulfone; (b) a surfactant reagent comprising a nonionic surfactant and a solvent; and (c) a nitrite reagent comprising a source of nitrite ion.
Claim 10
Dependent Claim
16 words
The kit of claim 6 wherein the mineral acid of the bilirubin reagent is hydrochloric acid.
Claim 11
Dependent Claim
31 words
The kit of claim 7 wherein the bilirubin reagent consists of a solution containing 0.5% w/v sulfanilic acid and 50% v/v tetramethylene sulfone and which is 0.18 N in hydrochloric acid.
Claim 12
Dependent Claim
44 words
The kit of claim 6 wherein the nonionic surfactant of the surfactant reagent is an ethoxylated alkyl phenol of the formula C 9 H 19 C 6 H 4 (OCH 2 CH 2 ) n OH wherein n has an average value of 4.
Claim 13
Dependent Claim
18 words
The kit of claim 9 wherein the surfactant reagent is 60% v/v nonionic surfactant and is 40% methanol.
Claim 14
Dependent Claim
18 words
The kit of claim 6 wherein the source of nitrite ion in the nitrite reagent is sodium nitrite.
Claim 15
Dependent Claim
17 words
The kit of claim 11 wherein the nitrite reagent is a 0.5% aqueous solution of sodium nitrite.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |