Evaluation of a new free-thyroxin assay
The Amerlex Free Thyroxin (T/sub 4/) Radioimmunoassay Kit (Amersham International Ltd.) is a new direct equilibrium radioimmunoassay for free T/sub 4/ based on an antiserum with very high affinity for T/sub 4/, and a unique /sup 125/l-labeled T/sub 4/ analog as tracer. It is a very simple single-tube radioimmunoassay, making use of Amerlex particles to separate antibody-bound from free species. Interassay precision (CV) is 3.7% at 13 pmol/L and 2.3% at 30 pmol/L; within-assay precision is 4.2% at 21 pmol/L. The reference interval is 11-22 pmol/L. The assay did not misclassify any patients tested who had untreated myxedema or untreated thyrotoxicosis. The free T/sub 4/ assay excelled both the free T/sub 4/ index and the T/sub 4//T/sub 4/-binding globulin ratio in correcting for increased thyroxin-binding globulin from pregnancy, and it was better than the index but not better than the ratio in correcting for increased thyroxin-binding globulin in users of oral contraceptives.
- Research Organization:
- Queen Elizabeth Hospital, Woodville, South Australia
- OSTI ID:
- 5799360
- Journal Information:
- Clin. Chem. (Winston-Salem, N.C.); (United States), Vol. 27:12
- Country of Publication:
- United States
- Language:
- English
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HYPERTHYROIDISM
DIAGNOSIS
HYPOTHYROIDISM
RADIOIMMUNOASSAY
EVALUATION
EXPERIMENTAL DATA
IODINE 125
MEASURING METHODS
PATIENTS
THYROXINE
TRACER TECHNIQUES
AMINO ACIDS
BETA DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
DATA
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE DISEASES
HORMONES
INFORMATION
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PEPTIDE HORMONES
RADIOASSAY
RADIOISOTOPES
THYROID HORMONES
550601* - Medicine- Unsealed Radionuclides in Diagnostics