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US4486531A
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Method and reagent for the determination of β-lipoprotein
Assignee: Roche Diagnostics GmbH
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Filing: 1983-05-04
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Granted: 1984-12-04
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Expires: 2003-05-04
Abstract
Abstract The present invention provides a process for the direct turbidimetric determination of beta -lipoproteins (LDL) in body fluids by precipitation with polyanions and divalent cations, wherein the precipitation is carried out in the presence of a complex former at a pH value of from 7 to 9. The present invention also provides a reagent for the direct turbidimetric determination of beta -lipoproteins (LDL) in body fluids, comprising a polyanion, a salt of a divalent metal, a complex former and a substance buffering at pH 7 to 9.
Inventors
- 👤 Joachim Ziegenhorn
- 👤 Knut Bartl
- 👤 Max Brandhuber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:21
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/34; C12Q1/44; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/92; G01N2800/00; G01N2800/04; G01N2800/044; Y; Y10; Y10S; Y10S435/00; Y10S435/81; Y10T; Y10T436/00; Y10T436/10; Y10T436/104165; Y10T436/105831; Y10T436/107497; Y10T436/25; Y10T436/25125; Y10T436/25375
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
99 words
A method for the direct turbidimetric determination of beta-lipoproteins (LDL) in body fluids, in the presence of pre-beta-lipoproteins (VLDL) and alpha-lipoproteins (HDL) consisting essentially of adding a test sample, to a mixture of 0.005% to 0.5% of a polyanion and 1 to 35 grams/l of a chelating agent for a divalent cation that is different than the polyanion, said mixture and sample being at a ph value of from 7 to 9; adding 0.01 to 0.3 m of the divalent cation to cause turbidity to form and, thereafter, measuring the turbidity formed to determine the quality of the LDL.
Claim 2
Independent Claim
99 words
A method for the direct turbidimetric determination of beta-lipoproteins (LDL) in body fluids, in the presence of pre-beta-lipoproteins (VLDL) and alpha-lipoproteins (HDL) consisting essentially of adding a test sample, to a mixture of 0.005% to 0.5% of a polyanion and 1 to 35 grams/l of a chelating agent for a divalent cation that is different than the polyanion, said mixture and sample being at a ph value of from 7 to 9; adding 0.01 to 0.3 m of the divalent cation to cause turbidity to form and, thereafter, measuring the turbidity formed to determine the quality of the LDL.
Claim 3
Dependent Claim
19 words
Method as claimed in claim 1 wherein an ester splitting enzyme is also added in carrying out the precipitation.
Claim 4
Dependent Claim
19 words
Method as claimed in claim 2 wherein a lipase from Rhizopus arrhizus is used as the ester splitting enzyme.
Claim 5
Dependent Claim
13 words
Method as claimed in claim 1 wherein said complex former is a poly-ligand.
Claim 6
Dependent Claim
12 words
Method as claimed in claim 4 wherein said poly-ligand is a hexaligand.
Claim 7
Dependent Claim
13 words
Method as claimed in claim 5 wherein the hexaligand is ethylenediamine-tetraacetic acid (EDTA).
Claim 8
Dependent Claim
16 words
Method as claimed in claim 1 wherein the cation used is an alkali earth metal cation.
Claim 9
Dependent Claim
14 words
Method as claimed in claim 1 wherein the cation used is a manganese cation.
Claim 10
Dependent Claim
14 words
Method as claimed in claim 1 wherein the cation used is a cobalt cation.
Claim 11
Dependent Claim
18 words
Method as claimed in claim 1 wherein the cation and complex former are used in equal molar amounts.
Claim 12
Dependent Claim
30 words
Method as claimed in claim 1 wherein the complex former and the cation are first reacted with one another and the salt-like complex formed is in carrying out the precipitation.
Claim 13
Dependent Claim
19 words
Method as claimed in claim 1 wherein heparin sodium, polyphosphotungstic acid or dextran sulphate is used as the polyanion.
Claim 14
Dependent Claim
21 words
Method as claimed in claim 1 wherein the determination is carried out kinetically by measurement in a predetermined period of time.
Claim 15
Dependent Claim
24 words
Method as claimed in claim 1 wherein tris(hydroxymethyl)-aminomethane hydrochloride triethanolamine hydrochloride or imidazole hydrochloride is used as a buffer to achieve the desired pH.
Claim 16
Dependent Claim
68 words
Reagent for the direct turbidimetric determination of beta-lipoproteins (LDL) in body fluids, in the presence of per-beta-lipoproteins (VLDL and alpha-lipoproteins (HDL) said reagent consisting essentially of -0.005% to 0.5% of a polyanion, 0.01 to 0.3 m of a salt of a divalent metal, and 1 to 35 grams per liter of a chelating agent for the divalent cation; and a buffer substance buffering at pH 7 to 9.
Claim 17
Dependent Claim
68 words
Reagent for the direct turbidimetric determination of beta-lipoproteins (LDL) in body fluids, in the presence of per-beta-lipoproteins (VLDL and alpha-lipoproteins (HDL) said reagent consisting essentially of -0.005% to 0.5% of a polyanion, 0.01 to 0.3 m of a salt of a divalent metal, and 1 to 35 grams per liter of a chelating agent for the divalent cation; and a buffer substance buffering at pH 7 to 9.
Claim 18
Dependent Claim
11 words
Reagent as claimed in claim 15 additionally containing an ester-splitting enzyme.
Claim 19
Dependent Claim
17 words
Reagent as claimed in claim 16 wherein the ester splitting enzyme is a lipase from Rhizopus arrhizus.
Claim 20
Dependent Claim
13 words
Reagent as claimed in claim 15 wherein the complex former is a poly-ligand.
Claim 21
Dependent Claim
12 words
Reagent as claimed in claim 18 wherein the poly-ligand is a hexaligand.
Claim 22
Dependent Claim
12 words
Reagent as claimed in claim 19 wherein the hexaligand is ethylenediamine-tetraacetic acid.
Claim 23
Dependent Claim
67 words
Reagent for the direct turbidimetric determination of beta-lipoproteins (LDL) in body fluids, which reagent comprises 0.02 to 0.5% by weight heparin sodium 30,000 to 75,000 USP, dextran sulphate or polyphosphotungstic acid; 2 to 35 grams per liter of a complex salt of calcium ions and ethylenediamine-tetraacetic acid; 15 to 50 mMol/liter calcium chloride; and 100 to 150 mMol/liter tris(hydroxymethyl)-aminomethane hydrochloride buffer having a pH 7 to 9.
Claim 24
Dependent Claim
67 words
Reagent for the direct turbidimetric determination of beta-lipoproteins (LDL) in body fluids, which reagent comprises 0.02 to 0.5% by weight heparin sodium 30,000 to 75,000 USP, dextran sulphate or polyphosphotungstic acid; 2 to 35 grams per liter of a complex salt of calcium ions and ethylenediamine-tetraacetic acid; 15 to 50 mMol/liter calcium chloride; and 100 to 150 mMol/liter tris(hydroxymethyl)-aminomethane hydrochloride buffer having a pH 7 to 9.
Claim 25
Dependent Claim
17 words
Reagent as claimed in claim 21 additionally containing 100 to 6000 U/liter of an ester splitting enzyme.
Claim 26
Dependent Claim
22 words
Reagent as claimed in claim 22 wherein the ester splitting enzyme is present in an amount of from 500 to 2000 U/liter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |