The use of a discontinuous density gradient and of a vertical rotor to separate plasma lipoproteins are modifications of Barter's described method for assaying cholesteryl ester transfer activity (CETA) in plasma. The original feature of our approach is the fast preparation of the labeled substrate by a physiologic-like process, which renders the assay easy and suitable for measurement of this activity in both man and animals.
Harvengt, C., Desager, J.-P., Mailleux, P., & Heller, F. R. (1989). An improvement of Barter’s method for assaying plasma cholesterol ester transfer activity: experimental and clinical applications. Biomedicine & Pharmacotherapy, 43(1), 53-58. https://doi.org/10.1016/0753-3322(89)90191-1 (Original work published 1989)