Figure 1.

Separation of Lp(a) by electrophoresis or by density gradient ultracentrifugation. (A): Lp(a) migrates in gel electrophoresis as an extra pre-β1 band and can be quantitated either after staining for lipids with Sudan black or by staining with a cholesterol reagent. Here Lp(a) is separated in a routine laboratory by the Helena^® Electrophoretic system, and the concentration is given as Lp(a)-cholesterol. Given the fact that Lp(a) consists of some 25–30% of cholesterol, Lp(a) mass in mg/dL may be obtained by a factor of 3–4. (B): The heterogeneity of Lp(a) may be demonstrated by density gradient ultracentrifugation. The serum proteins were pre-stained with Coomassie blue, and lipoproteins were separated in the SW-41 Rotor, Beckmann^® for 24 h at 40,000 RpM. In this plasma sample, some 75% of Lp(a) was found in the HDL₁ region, while the rest were distributed from the top to bottom fraction.