US3715188A
Expired / Lapsed
US
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Cholesterol assay and reagents therefor
Assignee: INDIANA DEVELOPMENT FINANCE AUTHORITY
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Filing: 1971-04-30
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Granted: 1973-02-06
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Expires: 1991-04-30
Abstract
Abstract A cholesterol assay, using formamide, which achieves the simplicity of a direct test of a specimen sample, yet which also achieves a comparable specificity and accuracy of cholesterol assays involving multiple-extraction steps. The formamide destroys the cholesterol chromophore of a blank measurement, and this result may be compared with a companion cholesterol assay to eliminate the error caused by the chromophore of non-cholesterol chromogenic substances of the specimen; and the formamide also keeps the alcohol, which is used to prevent turbidity, from blocking the formation of the bilirubin portion of the noncholesterol chromogenic substances.
Inventors
- 👤 J Denney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 21:34
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/92; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
46 words
A process for the quantitative colorimetric or spectrophotometric determination of cholesterol in serum, plasma, or other biological material to be tested, wherein the improvement comprises adding formamide to said material for preventing the formation of a chromophore from the cholesterol chromogen in the sample being assayed.
Claim 2
Dependent Claim
46 words
A process for the quantitative colorimetric or spectrophotometric determination of cholesterol in serum, plasma, or other biological material to be tested, wherein the improvement comprises adding formamide to said material for preventing the formation of a chromophore from the cholesterol chromogen in the sample being assayed.
Claim 3
Dependent Claim
72 words
The process as set forth in claim 1 in which the formamide is added to a first portion of said material to prevent the said formation of the cholesterol chromophore to provide a blank measurement, and in which formamide is omitted from a second portion of said material to provide a test measurement, and comparing the blank measurement with the test measurement, whereby a quantitative determination of the cholesterol itself is achieved.
Claim 4
Dependent Claim
59 words
A process for the quantitative determination of cholesterol in serum, plasma, or other biological material to be tested, wherein the improvement comprises adding formamide and a high molecular weight alcohol to said material for preventing the formation of chromophore from the cholesterol chromogen in the sample being assayed, while permitting the formation of the chromophore from the bilirubin chromogen.
Claim 5
Dependent Claim
59 words
A process for the quantitative determination of cholesterol in serum, plasma, or other biological material to be tested, wherein the improvement comprises adding formamide and a high molecular weight alcohol to said material for preventing the formation of chromophore from the cholesterol chromogen in the sample being assayed, while permitting the formation of the chromophore from the bilirubin chromogen.
Claim 6
Dependent Claim
19 words
The process as set forth in claim 3, the alcohol having from eight to sixteen carbon atoms per molecule.
Claim 7
Dependent Claim
15 words
The process as set forth in claim 3 in which the alcohol is tridecyl alcohol.
Claim 8
Dependent Claim
15 words
The process as ser forth in claim 3 in which the alcohol is hexadecyl alcohol.
Claim 9
Dependent Claim
21 words
The process as set forth in claim 3 in which the high molecular weight alcohol is added to the cholesterol reagent.
Claim 10
Dependent Claim
124 words
A process for the quantitative determination of cholesterol in serum, plasma, or other biological material to be tested, wherein the improvement comprises adding formamide to block the formation of the chromophore from the cholesterol chromogen in a first portion of the sample while causing the non-cholesterol chromogenic substances in the said first portion of the sample to produce their chromophores, and in a second portion of the sample the step of causing the formation of chromophore from the sample''s substance including both its said non-cholesterol chromogenic substances and its cholesterol chromogen, by omitting formamide, and comparing the chromophore of the two sample portions to quantitatively determine the cholesterol content of the sample by the contrast of the chromophore produced in the two sample portions.
Claim 11
Dependent Claim
124 words
A process for the quantitative determination of cholesterol in serum, plasma, or other biological material to be tested, wherein the improvement comprises adding formamide to block the formation of the chromophore from the cholesterol chromogen in a first portion of the sample while causing the non-cholesterol chromogenic substances in the said first portion of the sample to produce their chromophores, and in a second portion of the sample the step of causing the formation of chromophore from the sample''s substance including both its said non-cholesterol chromogenic substances and its cholesterol chromogen, by omitting formamide, and comparing the chromophore of the two sample portions to quantitatively determine the cholesterol content of the sample by the contrast of the chromophore produced in the two sample portions.
Claim 12
Dependent Claim
62 words
A process according to claim 8, in which a mixture of acetic acid, acetic anhydride, and sulfuric acid is added to the first and second portions to cause the non-cholesterol chromogenic substances in the said first portion of the sample to produce their chromophores and also to cause the formation of chromophore from the sample in the second portion of the reaction.
Claim 13
Dependent Claim
16 words
The process according to claim 9 in which the mixture includes a high molecular weight alcohol.
References Cited (Backward Citations)
US3558516A
Cited
US3615232A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |