Measurement of carnitine in hemodialysis patients – adaptation of an enzymatic photometric method for an automatic analyzer
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Roman Cibulka
Abstract
Background: The main goal of this work was to describe the analytical characteristics of an enzymatic photometric test for carnitine determination and its automation using an Olympus analyzer.
Methods: We used a test from Roche intended for manual processing and tried to apply it for use on an Olympus AU 400 analyzer. The analytical parameters of our modified technique were determined using external quality controls and kit controls, and by measurements in venous blood samples from 85 chronically hemodialyzed patients (before and after hemodialysis) and from 68 healthy blood donors serving as controls.
Results: A reference value for free carnitine was estimated parametrically as 40.1±17.8μmol/L. The mean bias for eight control measurements was 5.1%. Sensitivity was calculated as the limit of quantification at 2.6μmol/L. The intra-assay coefficient of variation was 2.4%. The inter-assay coefficient of variation was 8.3%. Analytical recovery was 101.8%, 99.5% and 95.4%.
Conclusions: The main advantages of our automated method in comparison to the original manual method are the smaller amounts of samples, reagents and diluents required and the shorter analysis time. As hemodialysis patients often suffer from carnitine deficiency, we conclude that its determination may be helpful for diagnostic verification.
Clin Chem Lab Med 2006;44:983–6.
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©2006 by Walter de Gruyter Berlin New York
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Articles in the same Issue
- Laboratory medicine in the 2000s: programmed death or rebirth?
- Polymorphisms of the inflammatory system and risk of ischemic cerebrovascular events
- Haptoglobin polymorphism in patients with preeclampsia
- Fifteen polymorphisms in endothelin-1, endothelin-2 and endothelin-receptor-A genotyped by four duplex assays and seven simple assays on a LightCycler using hybridization probes
- Optimization of an enzymatic method for the determination of lysosomal N-acetyl-β-D-hexosaminidase and β-glucuronidase in synovial fluid
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- Unchanged androgen-binding properties of sex hormone-binding globulin in male patients with liver cirrhosis
- Relationship between serum uric acid, creatinine, albumin and gestational diabetes mellitus
- Aminothiols in human brain tumors
- Measurement of carnitine in hemodialysis patients – adaptation of an enzymatic photometric method for an automatic analyzer
- A robust liquid chromatography tandem mass spectrometry method for total plasma homocysteine determination in clinical practice
- Establishment of reference distributions and decision values for thyroid antibodies against thyroid peroxidase (TPOAb), thyroglobulin (TgAb) and the thyrotropin receptor (TRAb)
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- Influence of the needle bore size used for collecting venous blood samples on routine clinical chemistry testing
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- Evaluation of the analytical performance of the advanced method for cardiac troponin I for the AxSYM platform: comparison with the old method and the Access system
- Preliminary performance evaluation of blood gas analyzers
- A cost-effectiveness evaluation of reticulocyte measurement in new outpatients with or without hematologic disorders
- Guidelines for setting up an External Quality Assessment Scheme for blood smear interpretation. Part II: survey preparation, statistical evaluation and reporting
- Free light chain testing in follow-up of multiple myeloma
- Blood reactive oxygen metabolites (ROMs) and total antioxidant status (TAS) in patients with laryngeal squamous cell carcinoma after surgical treatment
- SIBioC 2006 38th National Congress of the Italian Society of Clinical Biochemistry and Clinical Molecular Biology, Turin, Italy, September 19–22, 2006
- Third Santorini Biologie Prospective Conference 2006: From Human Genetic Variations to Prediction of Risks and Responses to Drugs and the Environment, Santorini Island, Greece, September 29 - October 2, 2006
