Immunoradiometric determination of thyroglobulin in serum samples by time calibration transfer
-
Luis Antonio Tortajada-Genaro
Abstract
Background: A limitation of isotopic assays is decay of the radioactive signal and the need for a calibration curve in each run. Thus, calibration transfer has been proposed for immunoradiometric analysis (IRMA). The present study was undertaken to establish the main methodological issues applied to the determination of thyroglobulin (Tg).
Methods: Serum samples were analyzed at a different experimental time than Tg standards. Tg concentrations were then determined using a transferred calibration curve estimated from a calibration model based on a three-parameter antigen-antibody interaction model and a decay kinetic constant.
Results: A kinetic constant for decay of the radiolabeled antibody signal was calculated (–0.018± 0.002 day−1). This strategy avoided full recalibration, despite degradation of the radiolabeled immunoreagents or experimental variations. The calibration transfer was validated using addition, dilution and recovery protocols. Repeated analyses of serum samples were performed during the life of the commercial immunoreagents, and concentrations were determined using daily and transferred calibration curves. Results were statistically comparable, but significant reductions in reagent consumption, analysis time, radioactive waste and staff time were obtained.
Conclusions: Transferred curves can be used to analyze samples by IRMA without simultaneous measurement of standards, and provide reliable concentrations. This principle has been demonstrated for Tg determination, but the key issues to extend to other IRMA methods have been established.
Clin Chem Lab Med 2008;46:1416–22.
©2008 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Review
- Use of biochemical markers of bone turnover in the management of postmenopausal osteoporosis
- Minireview
- Is serum procalcitonin able to predict long-term kidney morbidity from urinary tract infections in children?
- Genetics and Molecular Diagnostics
- Association between the 2756A> G variant in the gene encoding methionine synthase and myocardial infarction in Tunisian patients
- Common 894G>T single nucleotide polymorphism in the gene coding for endothelial nitric oxide synthase (eNOS) and risk of congenital heart defects
- New sequence variants in BRCA1 and BRCA2 genes detected by high-resolution melting analysis in an elderly healthy female population in Croatia
- Enzyme-free signal amplification of analyte in a single closed tube by fluorescent hybridization chain reaction
- Five X-chromosome short tandem repeats in a Western Mexican population
- General Clinical Chemistry and Laboratory Medicine
- Prolyl-hydroxyproline dipeptide in non-hydrolyzed morning urine and its value in postmenopausal osteoporosis
- Methionine metabolism in an animal model of sepsis
- Hypochlorous acid is a potent inactivator of human plasminogen at concentrations secreted by activated granulocytes
- Association of serum γ-glutamyltransferase with C-reactive protein levels and white blood cell count in Korean adults
- Immunoradiometric determination of thyroglobulin in serum samples by time calibration transfer
- Serum interleukin 6 (IL-6) and C-reactive protein (CRP) levels in colorectal adenoma and cancer patients
- Measurement of 10,11-dihydro-10-hydroxy-carbamazepine in serum and plasma by high-performance liquid chromatography
- The relationship between usual coffee consumption and serum C-reactive protein level in a Japanese female population
- Reference Values and Biological Variations
- Analytical quality goals for parathyroid hormone based on biological variation
- Preanalytical effects of pneumatic tube transport on routine haematology, coagulation parameters, platelet function and global coagulation
- Validation and Outcome Studies
- Automated immunoassay methods for ferritin: recovery studies to assess traceability to an international standard
- An expert system for the classification of serum protein electrophoresis patterns
- Impact of a satellite laboratory on turnaround times for the emergency department
- Effect of ampicillin-sulbactam on clinical capillary zone electrophoresis of serum proteins
- Guidelines and Recommendations
- Protein standardization V: value transfer. A practical protocol for the assignment of serum protein values from a Reference Material to a Target Material
- Letter to the Editor
- Biological variability evaluation and comparison of three different methods for C-peptide measurement
- Abstracts
- 10.1515/CCLM.2008.361
Articles in the same Issue
- Review
- Use of biochemical markers of bone turnover in the management of postmenopausal osteoporosis
- Minireview
- Is serum procalcitonin able to predict long-term kidney morbidity from urinary tract infections in children?
- Genetics and Molecular Diagnostics
- Association between the 2756A> G variant in the gene encoding methionine synthase and myocardial infarction in Tunisian patients
- Common 894G>T single nucleotide polymorphism in the gene coding for endothelial nitric oxide synthase (eNOS) and risk of congenital heart defects
- New sequence variants in BRCA1 and BRCA2 genes detected by high-resolution melting analysis in an elderly healthy female population in Croatia
- Enzyme-free signal amplification of analyte in a single closed tube by fluorescent hybridization chain reaction
- Five X-chromosome short tandem repeats in a Western Mexican population
- General Clinical Chemistry and Laboratory Medicine
- Prolyl-hydroxyproline dipeptide in non-hydrolyzed morning urine and its value in postmenopausal osteoporosis
- Methionine metabolism in an animal model of sepsis
- Hypochlorous acid is a potent inactivator of human plasminogen at concentrations secreted by activated granulocytes
- Association of serum γ-glutamyltransferase with C-reactive protein levels and white blood cell count in Korean adults
- Immunoradiometric determination of thyroglobulin in serum samples by time calibration transfer
- Serum interleukin 6 (IL-6) and C-reactive protein (CRP) levels in colorectal adenoma and cancer patients
- Measurement of 10,11-dihydro-10-hydroxy-carbamazepine in serum and plasma by high-performance liquid chromatography
- The relationship between usual coffee consumption and serum C-reactive protein level in a Japanese female population
- Reference Values and Biological Variations
- Analytical quality goals for parathyroid hormone based on biological variation
- Preanalytical effects of pneumatic tube transport on routine haematology, coagulation parameters, platelet function and global coagulation
- Validation and Outcome Studies
- Automated immunoassay methods for ferritin: recovery studies to assess traceability to an international standard
- An expert system for the classification of serum protein electrophoresis patterns
- Impact of a satellite laboratory on turnaround times for the emergency department
- Effect of ampicillin-sulbactam on clinical capillary zone electrophoresis of serum proteins
- Guidelines and Recommendations
- Protein standardization V: value transfer. A practical protocol for the assignment of serum protein values from a Reference Material to a Target Material
- Letter to the Editor
- Biological variability evaluation and comparison of three different methods for C-peptide measurement
- Abstracts
- 10.1515/CCLM.2008.361
