NIST and the National Cancer Institute cosponsored a workshop on August 18-19, 2005, to examine needs for reference materials for early cancer detection. This meeting focused on standards, methods, assays, reagents, and technologies. Needs for plasma and serum proteomics, DNA methylation, and specimen reference collections were discussed, and recommendations from participants were solicited. Th...

BACKGROUND The availability of commutable calibrator materials may ease considerably the task of harmonizing assay results and ensuring their traceability to reference procedures. We sought to verify the commutability of potential calibrator materials and evaluate their effectiveness in harmonizing LDH results by 2 measurement methods. METHODS We measured LDH in 109 serum samples and 31 mater...

We report mass-independent and mass-dependent Ca isotopic compositions for thirteen geological reference materials, including carbonates (NIST SRM 915a and 915b), Atlantic seawater as well as ten rock reference materials ranging from peridotite to sandstone, using traditional e and d values relative to NIST SRM 915a, respectively. Isotope ratio determinations were conducted by independent unspi...

These suggestions are as follows: 1) Regular use of certified reference materials and/or internal quality control using secondary reference materials 2) Participation in interlaboratory comparison or proficiency testing programs 3) Replicate tests or calibrations using the same or different methods 4) Retesting or recalibration of retained items 5) Correlation of results for different character...