Enzyme immunoassay of thyroxin with a centrifugal analyzer

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Clin. Chem. (Winston-Salem, N.C.); (United States)

OSTI ID:5639833

Izquierdo, J M; Sotorrio, P; Quiros, A

We have applied a homogeneous enzyme immunoassay for determination of thyroxinin serum to the ''Cobas Bio'' centrifugal analyzer. To unbind thyroxin from its protein complex, serum is treated for 20 min with a solution of NaOH containing ''Lipex,'' an agent for sequestering free fatty acids. The immunoenzymic reaction is then automatically performed by the analyzer at 37/sup 0/C. To 20 ..mu..L of sample mixture is added 125 ..mu..L of reagent (thyroxin antibodies and NAD/sup +/) and this mixture is incubated for 10 s. Then 25 ..mu..L of start reagent (enzyme-thyroxin conjugate and malate substrate) is added and the change in absorbance is monitored at 340 nm. The standard curve is linear up to at least 200 ..mu..g of thyroxin per liter. Within-assay precision (CV) varied from 1.1 to 2.9%, between-assay precision from 3.1 to 7.8%. Analytical recovery of thyroxin was complete. The deviation of control samples from target values ranged from -2.1% to 7.0%. Interference by hemoglobin or bilirubin is negligible. Results compare favorably with those by radioimmunoassay.

• Research Organization: Hospital General de Asturias, Oviedo, Spain
• OSTI ID: 5639833
• Journal Information: Clin. Chem. (Winston-Salem, N.C.); (United States), Journal Name: Clin. Chem. (Winston-Salem, N.C.); (United States) Vol. 28:1; ISSN CLCHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
BIOASSAY
BLOOD SERUM
CARBOXYLIC ACIDS
CENTRIFUGAL FAST ANALYZERS
CHEMICAL ANALYSIS
COMPARATIVE EVALUATIONS
DATA
ENZYMES
EXPERIMENTAL DATA
HORMONES
IMMUNE SERUMS
INFORMATION
LIGANDS
MEASURING METHODS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PEPTIDE HORMONES
PROTEINS
QUANTITATIVE CHEMICAL ANALYSIS
THYROID HORMONES
THYROXINE