Simplified Technic for Estimation of Serum

of serum lipoproteins separated by zone electrophoresis on fixed media. Numerous studies (1-4) have demonstrated that such meas-urements may be subject to significant inconsistencies. Many sources of error may be eliminated when lipoprotein measurements are made in terms of a particular lipid component such as cholesterol (5). Langan et al., (6) have proposed a lipoprotein cholesterol technic in which small amounts of serum are separated in duplicate by filter paper electrophoresis. One strip of each pair stained with Sudan Black B is used to locate alpha- and beta-lipoprotein bands on the undyed strip. Cholesterol is isolated from these areas on the filter paper by refluxing with chloroform-methanol (2:1) for several hours. Nury and Smith (7) utilized a shortened staining period and achieved satisfactory cholesterol recoveries by boiling filter paper segments for 10 mm. in the same solvent mixture. Recently Crawford (8) has reported a more detailed procedure for the staining and elution of lipoprotein cholesterol. While these methods employed the ferric chloride technic for the quantification of cholesterol (9), Anderson and Keys (10) made use of the Liebermann-Burchard reaction. These workers isolated cholesterol from strip segments by repeated extrac-tion with petroleum ether. After solvent evaporation the total choles