A simple turbidimetric assay designed for the routine screening as well as therapeutic monitoring of native LDL particles

• Published in: Clinica chimica acta 2001, Vol.303 (1), p.155-165
• Main Authors: Burns, Geoffrey, Kurrle-Weittenhiller, Angelika, Karl, Johann, Dieter Engel, Wolf, Grömping, Andreas, Boos, Karl-Siegfried, Seidel, Dietrich
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Cholesterol; Cholesterol, LDL - blood; Fundamental and applied biological sciences. Psychology; Humans; LDL; LDL particle; Lipoproteins, myelin; Low density lipoprotein; Nephelometry and Turbidimetry - methods; Proteins; Reproducibility of Results
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/S0009-8981(00)00395-8

We describe the development and performance of a homogeneous assay for the direct turbidimetric determination of LDL particles in human serum. The assay is based upon the specific agglutination of LDL particles by the polyanion PAMPS. The co-agglutination of VLDL is avoided by the addition of a zwitterionic detergent. Yielding results within 10 min, the assay requires only a small sample volume taken directly from primary serum tubes, i.e., no pretreatment of the sample is necessary. It can be easily applied to routine clinical chemistry analyzers. The results are highly correlated with LDL cholesterol determinations by ultracentrifugation ( r>0.95) and dextran sulfate precipitation ( r>0.95), but an increased recovery of small, high density LDL particles is observed, which more adequately reflects the atherogenic risk of LDL. The assay provides excellent intra- and inter-assay CVs in the range of 0.6–1.6 and 1.7–2.4%, respectively, on Roche Diagnostics/Hitachi analyzers. The method is well suited to the high-throughput screening of LDL cholesterol levels.