Publisher Summary This chapter discusses the extraction of lipid from lipoproteins. The separation of the lipid and the protein moieties can be achieved by extraction with a mixture of polar and non-polar organic solvents. This extract can be easily washed with water, which removes salts and peptides from the chloroform phase, but the high density of the solvent can make it difficult to collect the precipitate by centrifugation. The solvent most commonly used is a mixture of ethanol and ether. Both these components must be carefully re-distilled before use as they normally contain sufficient lipid-like material to be of consequence in some lipid determinations. Wet ethanol-ether has the disadvantage that it will dissolve substantial amounts of salt, as well as a little protein. The former can interfere with the running of thin-layer chromatograms, and the lipoprotein preparation should be subjected to a preliminary dialysis against 0.15 N NaCl. This step is essential in the case of high-density lipoprotein (HDL) preparations.