Establishment of a polyacrylamide gel electrophoresis-based method for measuring the size of low-density lipoprotein particles

Objective To establish a polyacrylamide gel electrophoresis(PAGE)-based method with high sensitivity and repeatability for measuring the size of low-density lipoprotein(LDL)particles.Methods LDL parti- cles were separated using 3%-16%polyacrylamide gradient gel electrophoresis,and the results were compared with those by density gradient ultraeentrifugation(DUC),which was considered as the golden standard.The intra- and inter-gel repeatability of the PAGE-based method was assessed,and the effect of serum preservation at-30℃and-70℃for up to 24 weeks on the size of the separated LDL particles was also evaluated.Results Compared to DUC method,the sensitivity and specificity of gradient PAGE was 70%and 100%,respectively;with the intra- and inter-gel difference being 0.44%and 2.05%,respectively.Preservation of the serum samples at-30℃or -70℃for 2,4,8,16 or 24 weeks did not result in significant variation in the size of the separated LDL particles. Conclusion 3%-16%gradient PAGE established in this study has good sensitivity and specificity for separating the LDL particles and is valuable for clinical and laboratory detection of small dense low-density lipoprotein.