Limits of quantization, LOQ, are calculated based on quality control runs performed over an at least 4 months period of regular use of the ICP-MS and the CV-AAS.
The laboratory is fully accredited with the Clinical Pathology Accreditation UK Ltd ,, has daily internal quality control run along with calibrators, and is judged fortnightly against its peers (external quality control).
Precision: The between assay variation calculated from the results of a quality control run in each assay (N = 50) gave the value 0.220 ± 0.018 nmol/l (coefficient of variation 8.2%).
A daily quality control run with a standard calibration kit from the manufacturer was performed to ensure proper focus, black and white level balance for each microscope objective, and linear camera output.
Inter-assay coefficients of variation calculated from the measurement of low, middle and high value quality controls run in each assay were 14.5%, 10.5% and 10.6%, respectively while intra-assay coefficients of variation values were 6.5%, 6.7% and 5.1%, respectively.
Inter-assay coefficients of variation calculated from the measurement of low, middle and high value quality controls ran in each assay were 9.0, 7.0 and 8.4 %.
Inter-assay coefficients of variation calculated from the measurement of low and high value quality controls ran in each assay were 0.6 and 1.4%%.
Optimized analytical HPLC for the 1 min quality control run was performed as described elsewhere (Nics et al. 2018).
All PCR products were subjected to quality control by running 5 μl of PCR product on a 2 % E-Gel® Agarose Gel Electrophoresis System (Life Technologies).
Daily quality control entails running "normal blood samples" in conjunction with the commercial control beads, and laboratories usually rely on donors to obtain normal samples; this may prove difficult owing to the need to find a donor on a day-to-day basis.
