Four electrophoretic methods compared for diagnosis of type III hyperlipoproteinemia.

Blood drawn from 192 probands and 1129 first-degree relatives who were participants in a collaborative family study of hyperlipoproteinemia at nine Lipid Research Clinics was used to prepare aliquots of whole plasma and top (d less than 1.006 g/mL) and bottom (d greater than 1.006 g/mL) ultracentrifugal fractions. Each aliquot was analyzed at a central laboratory by electrophoresis on paper, agarose, and polyacrylamide gel, and by a combined electrophoretic precipitation technique. The electrophoretograms were evaluated for the presence or absence of a "floating-beta" lipoprotein band. All four methods agreed completely for 92.3% of the samples. An additional 2.0% of the samples were in agreement for three electrophoretic methods, but the paper electrophoretic results were not interpretable. Another 1.9% were considered to be "floating-beta" positive by paper electrophoresis but negative by the other three electrophoretic methods.