Determination of iohexol and iothalamate in serum and urine by capillary electrophoresis.

Estimation of glomerular filtration rate (eGFR) is essential to assess kidney function. Iodine-containing contrast agents detection by HPLC has been proposed as a safe alternative for inulin or radioactive compounds. However, HPLC is a time-consuming and labor-intensive method.

Long-term stability of laboratory tests and practical implications for quality management.

Background: Long-term stability of analytical performance is required for adequate patient management. We investigated the use of patient data to document test stability, and the relevance of observed instabilities on a surrogate medical outcome. We used multiyear patient and internal quality control (IQC) data from two laboratories for tests to monitor chronic kidney and thyroid disease.

"Good samples make good assays" – the problem of sourcing clinical samples for a standardization project.

Clinical samples are the cornerstone in all aspects related to in vitro diagnostic testing. They are particularly valuable in the process of establishing/validating metrological traceability, because they eliminate commutability issues potentially associated with artificial calibrators. Therefore, they are essential for IFCC standardization projects.

IFCC international conventional reference procedure for the measurement of free thyroxine in serum: International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Working Group for Standardization of Thyroid Function Tests (WG-STFT)(1).

The IFCC Working Group for Standardization of Thyroid Function Tests proposes a candidate international conventional reference procedure (RMP) for measurement of the amount-of-substance concentration of free thyroxine in plasma/serum at physiological pH 7.40 and temperature (37.0°C).

Traceability to a common standard for protein measurements by immunoassay for in-vitro diagnostic purposes.

Background: There is a lot of confusion about the meaning of "measuring a protein in biological fluids" for in-vitro diagnostic purposes. This is due to a lack of understanding of metrological concepts and of acceptance of a pragmatic metrological concept for mixture analysis.

Methods: We describe the metrological concepts that apply to measurement of proteins.