Chemical precipitation of apolipoprotein B-containing lipoproteins facilitates determination of LDL particle size

Objectives: To simplify the determination of low-density lipoprotein (LDL) particle size by eliminating the need for ultracentrifugation. Design and Methods: We compared LDL particle size determination by gradient gel electrophoresis using two different methods for separation of LDL: (a) by ultracentrifugation with a density between 1.019 and 1.063 g/mL, and (b) by precipitation of the apolipoprotein B-containing lipoproteins from plasma. LDL particle size was determined for 41 individuals using both methods. Results: The correlation between these two methods was r = 0.98; peak particle diameter (nm) was reproducible with a coefficient of variation of 1.3% for LDL separated by ultracentrifugation and 1.4% for LDL prepared by precipitation. The intra-assay variation within a single gel was 0.2%. Conclusion: Elimination of the need for ultracentrifugation or lipid staining significantly reduces the cost and simplifies the procedure of LDL particle sizing. As a result, larger patient populations can be more readily screened for the determination of LDL particle size