US3887332A
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US
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Method of determining unsaturated iron binding capacity in serum
Assignee: Eiken Chemical Co Ltd
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Filing: 1973-04-05
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Granted: 1975-06-03
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Expires: 1993-04-05
Abstract
Abstract Unsaturated iron binding capacity of transferrin, a serum protein, is determined by adding an iron solution containing a known quantity of excess iron to the serum to saturate the iron binding capacity of the serum transferrin, removing the remaining surplus iron with an absorbent and making a colorimetric determination by causing iron to be released from transferrin under an acidic condition. Since the iron solution is unstable in alkaline zone, it is stabilized by forming it into nitrilotriacetic acid iron chelates. The stability of iron chelates of sodium bathophenanthroline sulfonate is greater than that of nitrilotriacetic acid. This fact is utilized, and the surplus quantity of nitrilotriacetic acid chelates remaining after the saturation of the iron binding capacity of tranferrin is measured by using sodium bathphenanthroline sulfonate. The sodium bathophenanthroline sulfonate iron chelates have maximum absorbance at the wavelength of 535 nm, and Beer''s law holds for an iron concentration range up to 600 mg/100 ml.
Inventors
- 👤 Kazuei Takase
- 👤 Junji Morikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:50
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/90; Y; Y10; Y10T; Y10T436/00; Y10T436/10; Y10T436/103332; Y10T436/107497; Y10T436/108331; Y10T436/109163
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
69 words
A METHOD OF DETERMINING THE UNSATURATED IRON BINDING CAPACITY OF TRANSFERRIN IN SERUM COMPRISING THE STEP OF: PREPARING A STANDARD SOLUTON OF IRON CHELATE IN WHICH A KNOWNAMOUNT OF IRON IS BOUND WITH NITRILOTRIACETIC ACID BY USING A BUFFER SOLUTION OF PH 8.4 TO 8.6; ADDIBG THE SAID STANDARD IRON SOLUTION TO A SAMPLE SERUM IN ORDER TO SATURATE THE IRON BINDING CAPACITY OF TRANSFERRIN IN THE SAID SERUM;
Claim 2
Independent Claim
69 words
A METHOD OF DETERMINING THE UNSATURATED IRON BINDING CAPACITY OF TRANSFERRIN IN SERUM COMPRISING THE STEP OF: PREPARING A STANDARD SOLUTON OF IRON CHELATE IN WHICH A KNOWNAMOUNT OF IRON IS BOUND WITH NITRILOTRIACETIC ACID BY USING A BUFFER SOLUTION OF PH 8.4 TO 8.6; ADDIBG THE SAID STANDARD IRON SOLUTION TO A SAMPLE SERUM IN ORDER TO SATURATE THE IRON BINDING CAPACITY OF TRANSFERRIN IN THE SAID SERUM;
Claim 3
Independent Claim
111 words
A method of determining the unsaturated iron binding capacity of transferrin in serum comprising the steps of: preparing a standard solution of iron chelate in which a known amount of iron is bound with nitrilotriacetic acid by using a buffer solution of pH 8.4 to 8.6; adding the said standard iron solution to a sample serum in order to saturate the iron binding capacity of transferrin in the said serum; reducing the excessive iron remaining unbound with transferrin by adding a salt of ascorbic acid to the said saturated solution; developing a color by adding sodium bathophenanthroline to the said reduced solution, and determining the absorbance of the said colored solution.
Claim 4
Independent Claim
111 words
A method of determining the unsaturated iron binding capacity of transferrin in serum comprising the steps of: preparing a standard solution of iron chelate in which a known amount of iron is bound with nitrilotriacetic acid by using a buffer solution of pH 8.4 to 8.6; adding the said standard iron solution to a sample serum in order to saturate the iron binding capacity of transferrin in the said serum; reducing the excessive iron remaining unbound with transferrin by adding a salt of ascorbic acid to the said saturated solution; developing a color by adding sodium bathophenanthroline to the said reduced solution, and determining the absorbance of the said colored solution.
Claim 5
Dependent Claim
24 words
The method as defined in claim 1, wherein said standard solution contains a small quantity of sodium ascorbate to serve as a reducing agent.
Claim 6
Independent Claim
223 words
A method of determining the unsaturated iron binding capacity of serum comprising the steps of: preparing four test tubes; preparing a sample serum by pouring 1.5 millilitres of a nitrilotriacetic acid buffer, 10 milligrams of a reducing agent, 0.5 millilitre of the serum and 0.05 millilitre of sodium bathophenanthroline sulfonate into a first one of said test tubes; preparing a serum blank by pouring 1.5 millilitres of a nitrilotriacetic acid iron buffer, 10 milligrams of said reducing agent, 0.5 millilitre of said serum and 0.05 millilitre of distilled water into a second one of said test tubes; preparing a standard iron solution by pouring 1.5 millilitres of said nitrilotriacetic acid iron buffer, 10 milligrams of said reducing agent, 0.5 millilitre of distilled water and 0.05 millilitre of a sodium bathophenanthroline sulfonate solution into a third one of said test tubes; preparing a reagent blank by pouring 1.5 millilitres of said nitrilotriacetic acid buffer, 10 milligrams of said reducing agent, 0.5 millilitre of distilled water and 0.05 millilitre of said sodium bathophenanthroline sulfonate solution into the last one of said test tubes; determining the absorbance at the wavelength of 535 nm of the respective samples in said test tubes by using water as reference; and calculating the value of the unsaturated iron binding capacity from the values of the absorbance of said respective sample.
Claim 7
Independent Claim
223 words
A method of determining the unsaturated iron binding capacity of serum comprising the steps of: preparing four test tubes; preparing a sample serum by pouring 1.5 millilitres of a nitrilotriacetic acid buffer, 10 milligrams of a reducing agent, 0.5 millilitre of the serum and 0.05 millilitre of sodium bathophenanthroline sulfonate into a first one of said test tubes; preparing a serum blank by pouring 1.5 millilitres of a nitrilotriacetic acid iron buffer, 10 milligrams of said reducing agent, 0.5 millilitre of said serum and 0.05 millilitre of distilled water into a second one of said test tubes; preparing a standard iron solution by pouring 1.5 millilitres of said nitrilotriacetic acid iron buffer, 10 milligrams of said reducing agent, 0.5 millilitre of distilled water and 0.05 millilitre of a sodium bathophenanthroline sulfonate solution into a third one of said test tubes; preparing a reagent blank by pouring 1.5 millilitres of said nitrilotriacetic acid buffer, 10 milligrams of said reducing agent, 0.5 millilitre of distilled water and 0.05 millilitre of said sodium bathophenanthroline sulfonate solution into the last one of said test tubes; determining the absorbance at the wavelength of 535 nm of the respective samples in said test tubes by using water as reference; and calculating the value of the unsaturated iron binding capacity from the values of the absorbance of said respective sample.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |