Rapid and simple method for the identification of apolipoprotein E isomorphic phenotypes from whole serum

For the identification of apolipoprotein E isomorphic phenotypes, fresh or thawed serum was analyzed without prior delipidation or other pretreatment. Using 5% polyacrylamide gels with a 40 mm interelectrode distance, the isoforms were separated by isoelectric focusing in immobilized pH gradients ranging from pH 5 to 6.5, and transferred onto polyvinylidene difluoride membranes by contact blotting for 1 h. The apolipoprotein E isoforms were identified following immunostaining. The electrophoresis required less than 2 h and the entire procedure could be completed within 6 h.