Measurement of lipoprotein particle sizes using dynamic light scattering

BackgroundA simple method for the measurement of LDL particle sizes is needed in clinical laboratories because a predominance of small, dense LDL (sd LDL) has been associated with coronary heart disease. We applied dynamic light scattering (DLS) to measure lipoprotein particle sizes, with special reference to sd LDL.MethodsHuman serum lipoproteins isolated by a combination of ultracentrifugation and gel chromatography, or by sequential ultracentrifugation, were measured for particle size using DLS.ResultsThe sizes of polystyrene beads, with diameters of 21 and 28 nm according to the manufacturer, were determined by DLS as 19.3 ± 1.0 nm (mean ± SD, n = 11) and 25.5 ± 1.0 nm, respectively. The coefficients of variation for the 21 and 28 nm beads were 5.1% and 3.8% (within-run, n = 11), and 2.9% and 6.2% (between-run, n = 3), respectively. The lipoprotein sizes determined by DLS for lipoprotein fractions isolated by chromatography were consistent with the elution profile. Whole serum, four isolated lipoprote...