Combined radioimmunoassay for triiodothyronine and thyroxine
A method for the combined radioimmunoassay for the hormones triiodothyronine (T-3) and thyroxine (T-4) in serum or plasma, wherein the radiolabeled t-3 and t-4 reagents are t-3 and t-4 labeled with the same radioisotope. The hormones are extracted from the serum or plasma sample and separated from their binding proteins by adsorption to a crosslinked dextran gel at a highly alkaline ph. After washing away the dissociated proteins, a predetermined limiting amount of t-3 antibody is incubated with the gel and thereafter radiolabeled t-3 which has become extracted from the gel by antibody binding is washed away. Excess t-3 antibody and a predetermined limiting amount of t-4 antibody are then incubated with the gel and radiolabeled t-3 and t-4 which has become extracted from the gel by antibody binding are thereafter washed away. The respective relative amounts of radiolabeled t-3 and t-4 retained by the gel after the incubations with the respective limiting amounts of t-3 and t-4 antibody are compared with standard results to quantitate the hormones in the sample. The use of excess t-3 antibody in the t-4 antibody incubation is critical to the accuracy of the method, enabling the use of the same radioisotope for radiolabeling t-3 and t-4.
- Assignee:
- Miles Laboratories Inc
- Patent Number(s):
- US 4225576
- OSTI ID:
- 6582287
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
BIOLOGICAL MATERIALS
BLOOD
BLOOD PLASMA
BLOOD SERUM
BODY FLUIDS
CARBOXYLIC ACIDS
HORMONES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PEPTIDE HORMONES
RADIOASSAY
RADIOIMMUNOASSAY
RADIOISOTOPES
THYROID HORMONES
THYROXINE
TRACER TECHNIQUES
TRIIODOTHYRONINE