Synthetic boundary cell in an analytical ultracentrifuge to determine the flotation coefficient of human serum lipoproteins.

Human serum lipoproteins were analyzed by a new modified synthetic boundary cell using an analytical ultracentrifuge. This cell allows the formation of the synthetic boundary at the bottom level of the cell with self-adjusting meniscus and baseline. Thus, the total amount of lipoproteins was seen as a single peak at first. During centrifugation, each component of the lipoproteins was separated according to its flotation characteristics. It was, therefore, possible to determine precisely all lipoprotein components, especially high-density lipoproteins, in the presence of a more rapidly migrating species and to calculate the flotation coefficient of each lipoprotein using the formula for sedimentation coefficient reported by Svedberg (Svedberg, T. (1925) Kolloid-Z. 36, 53-64.