How can someone separate the hdl molecule from cholesterol?

Lab tests: Cholesterol is combined in the body with proteins to form compounds known as lipoproteins. These proteins take many shapes and sizes. Laboratory tests can fractionate some of these into a group known as low density liporpoteins, or 'ldl' cholesterol which is often referred to as 'bad' cholesterol. Another fraction is high density lipoproteins or 'hdl' often reffered to as 'good' cholesterol.

Lipoprotein Tests: High density lipoprotein (HDL) can be quantified in various ways. Beyond simply measuring cholesterol in HDL (hdl-c), HDL particles can be characterized qualitatively by size (small, medium, large) via electrophesis or density (more dense, less dense) via ultracentrifugation, as well as quantitative by HDL particle number (total, large, medium, small hdl-p) via nuclear magnetic resonance (nmr).