All of the homogeneous assays have current certifications from the CDC CRMLN (www.
All five homogeneous assays reported to date have current CRMLN certifications, indicating that at least one instrument application has demonstrated acceptable agreement with the RM on relatively normal specimens.
4] Nonstandard abbreviations: ATP, Adult Treatment Panel; NCEP, National Cholesterol Education Program; CHD, coronary heart disease; TG, triglyceride; LDL-C and HDL-C, LDL- and HDL-cholesterol, respectively; TC, total cholesterol; TLC, therapeutic lifestyle change; BQ, [beta]-quantification; CRMLN
, Cholesterol Reference Method Laboratory Network; Lp(a), lipoprotein a; and CRP, C-reactive protein.
Therefore, the CRMLN laboratories developed and validated a modified dextran sulfate (50 000 Da) procedure as the Designated Comparison Method (DCM) to provide results approximately equivalent to those of the CDC RM but without the need for ultracentrifugation (56).
Clinical laboratories can promote standardization by encouraging suppliers of their reagent sets to participate in the CRMLN comparison process.
The performance requirements for CRMLN laboratories have evolved since the CRMLN was formed.
These criteria for CRMLN laboratory performance were also consistent with performance requirements needed to validate traceability of clinical laboratory measurements to the NRS/CHOL.
The LDL-C concentrations of the 29 samples involved in the interlaboratory survey were determined by the CRMLN Method (LDL-[C.
Roche], LDL-C measured by the Roche assay; CRMLN, Cholesterol Reference Method Laboratory Network; PPV, positive predictive value; NPV, negative predictive value; CI, confidence interval; and UC, ultracentrifugation.
CRMLN carefully considered using the CDC reference method for HDL-C, but it was deemed impractical for accuracy transfer via method comparisons that require 40 or more fresh serum specimens.
CDC shipped the QC materials to the CRMLN laboratories on dry ice.
maintains direct traceability to the CDC through a rigorous standardization program.