Measurement of lipoprotein particle sizes using dynamic light scattering

Area of Science:

• Biochemistry
• Analytical Chemistry
• Clinical Diagnostics

Background:

• A simple method for measuring LDL particle sizes is needed in clinical laboratories.
• A predominance of small, dense LDL (sd LDL) is associated with coronary heart disease.
• Dynamic Light Scattering (DLS) is proposed for lipoprotein particle size measurement, focusing on sd LDL.

Purpose of the Study:

• To evaluate the utility of Dynamic Light Scattering (DLS) for measuring lipoprotein particle sizes.
• To assess the DLS method's ability to differentiate between various LDL subfractions, particularly small, dense LDL (sd LDL).
• To determine the feasibility of using DLS in clinical laboratories for routine analysis.

Main Methods:

• Lipoprotein particles were isolated using ultracentrifugation and gel chromatography or sequential ultracentrifugation.
• Particle sizes were measured using Dynamic Light Scattering (DLS).
• The DLS method was validated using polystyrene beads of known sizes.

Main Results:

• DLS accurately determined the sizes of polystyrene beads (19.3 +/- 1.0 nm and 25.5 +/- 1.0 nm).
• Within-run and between-run coefficients of variation for bead size measurements were low (2.9%–6.2%).
• DLS successfully differentiated various lipoprotein fractions, including large LDL (21.5 +/- 0.8 nm) and sd LDL (20.3 +/- 1.1 nm).

Conclusions:

• The proposed DLS method is capable of differentiating lipoprotein particle sizes, including large LDL and sd LDL.
• DLS shows potential for use in clinical laboratories.
• The method may be employed in conjunction with convenient lipoprotein separation techniques.