US3970746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Immunoassay for the measurement of total thyroxine in blood serum
Assignee: Individual
•
Filing: 1974-09-05
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Granted: 1976-07-20
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Expires: 1994-09-05
Abstract
Abstract An immunoassay for the measurement of total thyroxine in blood serum which employs trichloracetic acid and base to precipitate or denature the protein to quantitatively extract thyroxine. This procedure along with the use of radioactively labeled T 4 antiserum, and the resin sponge to separate free and bound hormone, minimizes the number of steps required in the assay, which can be performed in the same tube in less than ninety minutes.
Inventors
- 👤 Bhartur Premachandra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:02
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/74; G01N33/78
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
A radioimmunoassay for the measurement of total thyroxine in a serum sample which comprises the steps of: mixing trichloroacetic acid and sodium hydroxide with the serum sample to form a mixture; adding radioactively labeled thyroxine antiserum to the mixture; permitting the mixture to equilibrate; placing in contact with the mixture a resin sponge comprising a polyurethane foam of intercommunicating cell type containing a strong base anion exchange resin; incubating the mixture and resin sponge; measuring the initial radioactivity of the combined mixture and resin sponge with suitable detecting means; removing the resin sponge from the mixture; washing the resin sponge; and measuring the residual radioactivity in the resin sponge.
Claim 2
Dependent Claim
109 words
A radioimmunoassay for the measurement of total thyroxine in a serum sample which comprises the steps of: mixing trichloroacetic acid and sodium hydroxide with the serum sample to form a mixture; adding radioactively labeled thyroxine antiserum to the mixture; permitting the mixture to equilibrate; placing in contact with the mixture a resin sponge comprising a polyurethane foam of intercommunicating cell type containing a strong base anion exchange resin; incubating the mixture and resin sponge; measuring the initial radioactivity of the combined mixture and resin sponge with suitable detecting means; removing the resin sponge from the mixture; washing the resin sponge; and measuring the residual radioactivity in the resin sponge.
Claim 3
Dependent Claim
35 words
The radioimmunoassay of claim 1 in which thyroxine antiserum labeled with 125 I--T 4 is allowed to react with T 4 present in serum and in the presence of T 4 extracting solvent (acid-base mix).
Claim 4
Dependent Claim
18 words
The radioimmunoassay of claim 2 in which the mixture and resin sponge is incubated for about 1 hour.
Claim 5
Dependent Claim
17 words
The radioimmunoassay of claim 3 in which the trichloroacetic acid has a concentration of less than 40%.
Claim 6
Dependent Claim
36 words
The radioimmunoassay of claim 4 in which 0.1 milliliter of a 30% solution of trichloroacetic acid and 0.3 milliliter of an 0.75 normal solution of sodium hydroxide is added to 25 microliters of the serum sample.
References Cited (Backward Citations)
US3206602A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |