US4023933A
Expired / Lapsed
US
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Protein-assay reagent and method
Assignee: University of Georgia Research Foundation Inc
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Filing: 1976-06-10
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Granted: 1977-05-17
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Expires: 1996-06-10
Abstract
Abstract A dye binding reagent for protein assay comprises Coomassie Brilliant Blue G-250 and an acid having a pKa of from 1 to 2. Upon addition of the reagent to a protein-containing solution, the attendant color change can be spectrophotometrically measured to quantitate even micrograms of protein. Furthermore, the reagent is applicable to a wide range of proteins and requires only about 2 minutes for measurement. Addition of an alcohol such as ethanol to the reagent further improves sensitivity.
Inventors
- 👤 Marion M. Bradford
- 👤 William L. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:33
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/68; G01N33/6803; G01N33/6827; G01N33/6839
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
23 words
A reagent for use in protein assay which comprises the dye: ##STR2## and an acid having a pKa of from 0 to 4.
Claim 2
Dependent Claim
23 words
A reagent for use in protein assay which comprises the dye: ##STR2## and an acid having a pKa of from 0 to 4.
Claim 3
Dependent Claim
16 words
The reagent of claim 1, wherein the acid has a pKa of from 1 to 2.
Claim 4
Dependent Claim
11 words
The reagent of claim 1, wherein the acid is phosphoric acid.
Claim 5
Dependent Claim
17 words
The reagent of claim 1, wherein the pH of the resultant solution is from -1 to 1.
Claim 6
Dependent Claim
27 words
The reagent of claim 1, wherein the concentration of said dye is from 0.001 to 0.1% (w/v) and of said acid is from 4 to 12% (w/v).
Claim 7
Dependent Claim
10 words
The reagent of claim 1, which further comprises an alcohol.
Claim 8
Dependent Claim
15 words
The reagent of claim 6, which contains from 0 to 10% (w/v) of said alcohol.
Claim 9
Dependent Claim
10 words
The reagent of claim 6, wherein said alcohol is ethanol.
Claim 10
Dependent Claim
31 words
The reagent of claim 6, which contains from 0.005 to 0.05% (w/v) of said dye, from 7.5 to 9.5% (w/v) of phosphoric acid and from 4 to 5% (w/v) of ethanol.
Claim 11
Independent Claim
35 words
A method of assaying protein which comprises mixing a reagent comprising the dye ##STR3## and an acid having a pKa of from 0 to 4 and a protein-containing sample and observing the resultant color change.
Claim 12
Independent Claim
35 words
A method of assaying protein which comprises mixing a reagent comprising the dye ##STR3## and an acid having a pKa of from 0 to 4 and a protein-containing sample and observing the resultant color change.
Claim 13
Dependent Claim
20 words
The method of claim 10, wherein said change is monitored spectrophotometrically at a wavelength of from 570 to 620 nm.
Claim 14
Dependent Claim
26 words
The method of claim 10, wherein from 0.1 to 1 ml of said reagent is added for up to 25 μg of protein in said sample.
Claim 15
Dependent Claim
23 words
The method of claim 10, wherein the protein is selected from the group consisting of albumin, hemoglobin, globulin, chymotrypsinogen A and cytochrome C.
Claim 16
Dependent Claim
12 words
The method of claim 10, wherein the protein containing sample is urine.
Claim 17
Dependent Claim
12 words
The method of claim 10, wherein the protein-containing sample is spinal fluid.
Claim 18
Dependent Claim
11 words
The method of claim 10, wherein the acid is phosphoric acid.
Claim 19
Dependent Claim
17 words
The method of claim 10, wherein the pH of the resultant solution is from -1 to 1.
Claim 20
Dependent Claim
27 words
The method of claim 10, wherein the concentration of said dye is from 0.001 to 0.1% (w/v) and of said acid is from 4 to 12% (w/v).
Claim 21
Dependent Claim
12 words
The method of claim 10, wherein said reagent further comprises an alcohol.
Claim 22
Dependent Claim
17 words
The method of claim 19, wherein said reagent contains from 0 to 10% (w/v) of said alcohol.
Claim 23
Dependent Claim
10 words
The method of claim 19, wherein said alcohol is ethanol.
Claim 24
Dependent Claim
11 words
The method of claim 10, wherein an automated analyzer is employed.
Claim 25
Independent Claim
46 words
A method of assaying protein which comprises mixing a reagent which contains from 0.005 to 0.05% (w/v) of ##STR4## from 7.5 to 9.5% (w/v) of phosphoric acid and from 4 to 5% (w/v) of ethanol, and a protein containing sample and observing the resultant color change.
Claim 26
Independent Claim
46 words
A method of assaying protein which comprises mixing a reagent which contains from 0.005 to 0.05% (w/v) of ##STR4## from 7.5 to 9.5% (w/v) of phosphoric acid and from 4 to 5% (w/v) of ethanol, and a protein containing sample and observing the resultant color change.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |