US3894843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Determination of serum creatinine
Assignee: Beckman Coulter Diagnostics Inc
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Filing: 1974-03-04
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Granted: 1975-07-15
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Expires: 1994-03-04
Abstract
Abstract A colorimetric process for the quantitative determination of creatinine in blood serum or urine wherein an alkaline pH in the approximate range of 11.0 to 13.5 is maintained during colorimetry evaluation and in which urea and a detergent are caused to react simultaneously and synergistically with the serum or urine protein to prevent extraneous chromogen formation in the conventional alkaline-picrate reaction for creatinine.
Inventors
- 👤 Alvar Jarvis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:13
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/70; Y; Y10; Y10T; Y10T436/00; Y10T436/10; Y10T436/14; Y10T436/145555; Y10T436/147777
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
112 words
A COLORIMETRIC PROCESS FOR THE DETERMINATION OF CREATIMINE IN A BIOLOGIC FLUID SAMPLE CONTAINING PROTEINS COMPRISING, A. ADDING A REAGENT TO THE BIOLOGIC FLUID WHICH FORMS A COLORED COMPLEX HAVING A CHARACTERISTIC WAVELENGTH OF MAXIMUM LIGHT ABSORPTION WIH THE CREATININE IN SAID FLUID, WHILE PREVENTING THE INTERFERENCE OF PROTEIN WITH THE DESIRED DETERMINATION BY FORMING PROTEIN COMPLEXES WHICH PREVENT FORMATION OF EXTRANEOUS CHROMOGENS OF A NON-CREATININE CHARACTER, B. MEASURING THE DEGREE OF LIGHT ABSORPTION AT SAID CHARACTERISTIC WAVELENGTH, AND C. DETERMINING THE CREATININE CONCENTRATION IN SAID FLUID BY COMPARING THE MEASURED DEGREE OF LIGHT ABSORPTION WITH VALUES OF LIGHT ABSORPTION OBTAINED FROM STANDARD AQUEOUS SOLUTIONS CONTAINING THE REAGENT AND KNOWN CREATININE CONCENTRATIONS.
Claim 2
Dependent Claim
112 words
A COLORIMETRIC PROCESS FOR THE DETERMINATION OF CREATIMINE IN A BIOLOGIC FLUID SAMPLE CONTAINING PROTEINS COMPRISING, A. ADDING A REAGENT TO THE BIOLOGIC FLUID WHICH FORMS A COLORED COMPLEX HAVING A CHARACTERISTIC WAVELENGTH OF MAXIMUM LIGHT ABSORPTION WIH THE CREATININE IN SAID FLUID, WHILE PREVENTING THE INTERFERENCE OF PROTEIN WITH THE DESIRED DETERMINATION BY FORMING PROTEIN COMPLEXES WHICH PREVENT FORMATION OF EXTRANEOUS CHROMOGENS OF A NON-CREATININE CHARACTER, B. MEASURING THE DEGREE OF LIGHT ABSORPTION AT SAID CHARACTERISTIC WAVELENGTH, AND C. DETERMINING THE CREATININE CONCENTRATION IN SAID FLUID BY COMPARING THE MEASURED DEGREE OF LIGHT ABSORPTION WITH VALUES OF LIGHT ABSORPTION OBTAINED FROM STANDARD AQUEOUS SOLUTIONS CONTAINING THE REAGENT AND KNOWN CREATININE CONCENTRATIONS.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein urea is added to the sample prior to colorimetric determinations being made in an amount sufficient to form such protein complexes.
Claim 4
Dependent Claim
21 words
The process of claim 2 wherein a detergent is added to the urea and the combination is then added to sample.
Claim 5
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium octyl sulfate.
Claim 6
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium tetradecyl sulfate.
Claim 7
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium heptadecyl sulfate.
Claim 8
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium cetyl sulfate.
Claim 9
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium dodecyl sulfate.
Claim 10
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium myristyl sulfate.
Claim 11
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium octadecyl sulfate.
Claim 12
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium oleyl sulfate.
Claim 13
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is sodium tridecyl sulfate.
Claim 14
Dependent Claim
13 words
The process of claim 3 wherein the detergent selected is dodecyl benzene sulfate.
Claim 15
Dependent Claim
17 words
The process of claim 3 wherein the detergent comprises a sodium, potassium or lithium aralkane sulfate solution.
Claim 16
Dependent Claim
17 words
The process of claim 3 wherein sample size of sample is maintained from 0.01 to 2.0 ml.
Claim 17
Dependent Claim
17 words
The process of claim 3 wherein the volume of reagent is maintained from 0.2 to 25.0 ml.
Claim 18
Dependent Claim
15 words
The process of claim 3 wherein pH is maintained from 11.0 to 13.5 during colorimetry.
Claim 19
Dependent Claim
24 words
The process of claim 3 wherein a buffer is added to the reagent to maintain a pH of between 11.0 to 13.5 during colorimetry.
Claim 20
Dependent Claim
89 words
A reagent system for use in the determination of creatinine in a biological fluid sample containing proteins and in which the creatinine concentration in the sample is determined by comparing the measured degree of light adsorption with values of light adsorption obtained from standard solutions; A. Saturated picric acid solution in distilled water; and B. i. urea solution; ii. a buffered solution of sodium borate in a phosphate salt of sodium or potassium buffered to a pH of between 11.0 to 13.5; and iii. an aralkane sulphate detergent solution.
Claim 21
Dependent Claim
89 words
A reagent system for use in the determination of creatinine in a biological fluid sample containing proteins and in which the creatinine concentration in the sample is determined by comparing the measured degree of light adsorption with values of light adsorption obtained from standard solutions; A. Saturated picric acid solution in distilled water; and B. i. urea solution; ii. a buffered solution of sodium borate in a phosphate salt of sodium or potassium buffered to a pH of between 11.0 to 13.5; and iii. an aralkane sulphate detergent solution.
Claim 22
Dependent Claim
31 words
The reagent system of claim 19 in which the solution of Part A is mixed with the solution of Part B to provide an alkaline-picrate reagent used in the creatinine determination.
Claim 23
Dependent Claim
38 words
The reagent system as claimed in claim 20 in which the alkaline-picrate reagent is preincubated at 37* C. and then the sample is introduced into the reagent and incubated at 37* C. for from 10 to 30 minutes.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |