US4168207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
TBG assay
Assignee: Siemens Healthcare Diagnostics GmbH Germany
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Filing: 1977-08-03
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Granted: 1979-09-18
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Expires: 1997-08-03
Abstract
Abstract Method and compositions are provided for determining the thyroxine binding capacity of serum, the value finding use in determinations of free thyroxine index. A competitive assay is performed where antibody for T-3 (anti-triiodothyronine) and serum thyroxine binding sites compete for T-3(triiodothyronine) in the assay medium: the T-3 is present as free T-3 added in a predetermined amount and T-3 conjugated to an enzyme. By combining the materials in a buffered aqueous medium with enzyme substrates, and determining the rate of reaction by the changing concentration of a light absorptive substance over a predetermined period of time, the thyroxine binding capacity of the serum can be determined.
Inventors
- 👤 Robert A. Yoshida
- 👤 Joel E. Lavine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:40
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/74; G01N33/78
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
122 words
A method for determining thyroxine binding capacity of a serum sample which comprises: (1) combining in an aqueous medium at a pH in the range of about 5 to 10 under conditions which allow triiodothyronine to bind to available thyroxine binding globulin binding sites: (a) said serum sample ; (b) a predetermined amount of triiodothyronine in substantial excess over endogenous triiodothyronine and in the range of about 0.25 to 5 ng/ml in said assay medium; (c) anti(triiodothyronine); and (d) enzyme-bound-triiodothyronine wherein the activity of said enzyme-bound-triiodothyronine is diminished upon binding to anti(triiodothyronine); and (2) determining the enzyme activity of said enzyme-bound-triiodothyronine in said assay medium as compared to the enzyme activity determined with a serum sample having a known thyroxine binding capacity.
Claim 2
Independent Claim
122 words
A method for determining thyroxine binding capacity of a serum sample which comprises: (1) combining in an aqueous medium at a pH in the range of about 5 to 10 under conditions which allow triiodothyronine to bind to available thyroxine binding globulin binding sites: (a) said serum sample ; (b) a predetermined amount of triiodothyronine in substantial excess over endogenous triiodothyronine and in the range of about 0.25 to 5 ng/ml in said assay medium; (c) anti(triiodothyronine); and (d) enzyme-bound-triiodothyronine wherein the activity of said enzyme-bound-triiodothyronine is diminished upon binding to anti(triiodothyronine); and (2) determining the enzyme activity of said enzyme-bound-triiodothyronine in said assay medium as compared to the enzyme activity determined with a serum sample having a known thyroxine binding capacity.
Claim 3
Dependent Claim
37 words
A method according to claim 1, wherein said enzyme is malate dehydrogenase and said determining is performed by introducing malate and NAD and determining the change in light absorption over a predetermined time at about 340 nm.
Claim 4
Dependent Claim
14 words
A method according to claim 2, wherein said malate dehydrogenase is heart malate dehydrogenase.
Claim 5
Dependent Claim
18 words
A method according to claim 2, wherein said serum sample is of from about 10 to 50 μl.
Claim 6
Dependent Claim
42 words
A method according to claim 2, wherein the ratio of enzyme-bound-triiodothyronine and anti(triiodothyronine) provides a change in mOD at 340 nm at about 30° C. in the range of about 250 to 600 over a period of at least about 5 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) | 1982-09-17 | 1983-03-19 | 1983-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-17 | 1987-03-19 | 1987-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-17 | 1991-03-19 | 1991-09-18 | $7700.00 | Window Closed / Lapsed |