Abstract: A diagnostic device is provided that determines the activity of CETP by the use of a new synthesized donor particle. The method in the diagnostic device for measuring the activity of cholesteryl ester transfer protein comprises: adding a prepared sonicated particle to a buffer to form a buffered solution, adding an Intralipid emulsion to the buffered solution for the purpose of accepting the transfer of neutral lipid, adding cholesteryl ester transfer protein to the buffered solution incubating the buffered solution, and reading the fluorescence of the buffer solution to measure the activity of the cholesteryl ester transfer protein. The synthesized donor particle is representative of a high density lipoprotein and comprises a fluorescent group, N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino-covalently bound to a cholesteryl ester to form a NBD-CE core, a monolayer of phospholipid that surrounds the NBD-CE core and an apolipoprotein apoA-I associated with the monolayer and an aqueous phase.