Capillary electrophoretic analysis of recombinant human apolipoprotein E. Calibration mode of a protein reference...

Actual lack of standardization of serum apolipoprotein (apo) E measurements prevents intensive studies on the significance of apoE concentration in clinical chemistry. For this purpose the use of standards calibrated against a common reference material is essential in order to obtain reliable results. The assignment of a certified value to this reference material involves the use of an accurate and non immunological technique. We demonstrate here that capillary electrophoresis in sodium dodecyl sulfate containing gel (SDS-CGE) can be a method of choice. ApoE quantification was performed according to the peak area and a standard solution of purified apoAI. We obtained very close results to that obtained by HPLC of phenylalanine apoE content measurement i.e., 81.6 mg/l versus 84.6 mg/l and concluded that the SDS-CGE analysis is an accurate and reliable method for the certification of an apoE reference material to be used in serum apoE concentration measurements. The SDS-CGE combines advantages of SDS-polyacrylamide gel electrophoresis (high resolving power, rapidity and tolerance of complex sample) with that of quantitative HPLC analysis (accuracy, precision, linearity and speed).