The evaluation of the scoring systems: the fixed effects model under known variances.

A number of scoring systems for proficiency testing and interlaboratory comparison are in use by the metrology community. The choice of scoring system for a given study is often based on the study coordinator's experience and anecdotal knowledge, perhaps attributable to a historic lack of detailed and formal explanation about the foundation of these systems. This has influenced the development of new scoring systems, some of them departing from the well-established hypothesis testing theory.

An international assessment of the metrological equivalence of higher-order measurement services for creatinine in serum.

The Consultative committee for amount of substance-metrology in chemistry (CCQM)-K80 Key Comparison directly assessed the equivalence of many of the world's higher-order value-assigned materials (HOVAMs) for creatinine in human serum. This 2009 international study compared the certified values and uncertainties of the materials using measurements made under repeatability conditions. The study evaluated 17 materials submitted by 6 national metrology institutes (NMIs).

A Bayesian approach to the evaluation of comparisons of individually value-assigned reference materials.

Several recent international comparison studies used a relatively novel experimental design to evaluate the measurement capabilities of participating organizations. These studies compared the values assigned by each participant to one or more qualitatively similar materials with measurements made on all of the materials by one laboratory under repeatability conditions. A statistical model was then established relating the values to the repeatability measurements; the extent of agreement between the assigned value(s) and the consensus model reflected the participants' measurement capabilities.

A quantitative LC-MS/MS method for comparative analysis of capture-antibody affinity toward protein antigens.

A mass spectrometry-based antibody selection procedure was developed to evaluate optimal 'capture' monoclonal antibodies that can be used in a variety of analytical measurement applications. The isotope-dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS) methodology is based on the use of multiple-reaction monitoring of tryptic peptide fragments derived from protein antigens. A panel of monoclonal antibodies (mAb) was evaluated based on a quantitative determination of relative binding affinity to human cardiac troponin I following immunoprecipitation.